user12651: My limited understanding of Buddhism has already helped me in many ways and I am very glad to have found it. 
With that said, I have always wondered about this title question. If there is no 'I', then why do 'I' do anything? If we can consider ourselves to be just part of everything else, where does the motivation to do anything come from? Surely we admit that there is a self whenever we perform an action (and thus reveal a motivation that must have originated from a self). If there truly is no self, surely we would all just freeze motionless, die and return to nothingness. 
Apologies if this is an ignorant question. I am still feeling my way around this whole concept.

user254: I guess a simplistic (or "simplest possible") answer might be that we do things out of ignorance, greed, and (maybe) aversion too.
And maybe other motives are identified, in the Opposite wholesome qualities:

The three wholesome mental factors that are identified as the opposites of the three poisons are:

amoha (non-delusion) or prajna (wisdom)
alobha (non-attachment) or dāna (generosity)
adveṣa (non-hatred) or mettā (loving-kindness)


Also I'm not sure about your premise, that "there is no I" or even than there might be no I.
So far as I understand it, questions about whether the self exists or doesn't exist, will exist, won't exist, used to exist, and so on, lead to a "thicket of views" and not to liberation:

This is how he attends inappropriately: 'Was I in the past? Was I not in the past? What was I in the past? How was I in the past? Having been what, what was I in the past? Shall I be in the future? Shall I not be in the future? What shall I be in the future? How shall I be in the future? Having been what, what shall I be in the future?' Or else he is inwardly perplexed about the immediate present: 'Am I? Am I not? What am I? How am I? Where has this being come from? Where is it bound?'
"As he attends inappropriately in this way, one of six kinds of view arises in him: The view I have a self arises in him as true & established, or the view I have no self... or the view It is precisely by means of self that I perceive self... or the view It is precisely by means of self that I perceive not-self... or the view It is precisely by means of not-self that I perceive self arises in him as true & established, or else he has a view like this: This very self of mine — the knower that is sensitive here & there to the ripening of good & bad actions — is the self of mine that is constant, everlasting, eternal, not subject to change, and will stay just as it is for eternity. This is called a thicket of views, a wilderness of views, a contortion of views, a writhing of views, a fetter of views. Bound by a fetter of views, the uninstructed run-of-the-mill person is not freed from birth, aging, & death, from sorrow, lamentation, pain, distress, & despair. He is not freed, I tell you, from suffering & stress.

Also, any view-of-self leads to suffering (see this answer for details and references) ... and I think that "view of self" includes "I exist" and "I don't exist": these would both be considered self-views.

user-1: Experiances come into being by causes and so does a notion of "I" or "self" (one of the governing princibles). It's wrong to think that the way to liberation is primaly done by placing the strategy of not-self to it. A good and healthy self-esteem is a fundamental reqirement, and since nothing is more dear to being than one self, it's actually the drive to liberation.
Some very good explainings how to apply certain self and not-self strategies for going beyond all kind of self-views is certainly given in the teachings of: Selves & Not-self: The Buddhist Teaching on Anatta
Experiment with it and find out by yourself, using the basics, generosity and virtue as guides while walking toward concentation and seeing as it is.
And yes...

Doing the Math
The Dhamma is like doing math. There's multiplication, division, addition, and subtraction. If we can think in this way, we'll be intelligent. We know the right time and place for things. We subtract when we should subtract, multiply when we should multiply, divide when we should divide, add together when we should add together. If we multiply every time, our hearts will die from the burden. In other words, we have no sense of enough. No sense of enough means no sense that we're growing old.
Anyone with a sense of growing old is a person with a sense of enough. When there's enough, the words, "Okay, that's plenty," can make their way up. If there's not enough, that "okay" can't make its way up because we keep on wanting to take. We've never thrown anything away, let anything go, put anything down. We're always taking. If we can "okay," we're at ease. That's enough.

[Note: This is a gift of Dhamma and not meant for commercial purpose or other low wordily gains by means of trade and exchange.]

user8157: When not-self is fully realised there isn't anything to do; apart from to help others realise not-self. That is why the suttas say about the fully enlightened state of mind: "There is nothing further in this world". Because the full realisation of not-self is the supreme liberation or happiness, the fully enlightened person only performs compassionate actions to help others realise not-self. 

user151: No matter if we do or do not have a self
The view that we "surely have a self or soul", 
drives our desire to propel through life.
We want to be & to do & to exist.
So the goal of the practice is to:

let go of the desire to be anything.
let go of the desire to do anything.
let go of the desire not to be anything.
let go of the desire not to do anything.


user11541: It is not that you existed and then you ceased to be after learning Buddhism. You never existed. You did no action. Your identity of self was an illusion. If you did not do any anything in the past then will you do anything in the future ? No.
If you did not do anything in the past then will you do anything in the present ? No.
Give up the identity of Self. Give up the desire to be Mr. Somebody. None of the identities are worth identifying as Self.

user13443: It is not that there is no self. There is no self in the way you think of a self. That is, there in nothing inherent in what you refer to as "I".
When you understand this, you free yourself and your actions are able to transcend limits. With this understanding, your actions become perfections.
Which is why everything you do should be with an understanding of selflessness.

user4903: It essentially doesn't change anything. If you look hard, that "I" was always an illusion. No matter where you try to draw a boundary - it is artificial:

Does the body belong to the self or not? How about that constant flow of matter and energy in and out - at what point does it even belong to the body?
Do thoughts belong to the self or not? You are hopefully aware how much of your thoughts are triggered by others, or even just repeat outside influences. Often they are even rationalizations of what you just did for other reasons.
Do feelings belong to the self or not? Much of these are determined by past experiences, your situation, even medications, weather, food.

So, to keep up this delusion of an "I" separate from the rest of the world requires carefully ignoring all things saying otherwise, which is stressful, even harmful to keep up. If you let that drop away, you'll function as you always did, but with loads of more peace. Don't worry - if this body is hungry it will eat, no matter whether you create such mental complications around that process - or not.

12651: <p>My limited understanding of Buddhism has already helped me in many ways and I am very glad to have found it. </p>

<p>With that said, I have always wondered about this title question. If there is no 'I', then why do 'I' do anything? If we can consider ourselves to be just part of everything else, where does the motivation to do anything come from? Surely we admit that there is a self whenever we perform an action (and thus reveal a motivation that must have originated from a self). If there truly is no self, surely we would all just freeze motionless, die and return to nothingness. </p>

<p>Apologies if this is an ignorant question. I am still feeling my way around this whole concept.</p>
 254: <p>I guess a simplistic (or "simplest possible") answer might be that we do things out of <a href="https://en.wikipedia.org/wiki/Three_poisons" rel="nofollow noreferrer">ignorance, greed, and (maybe) aversion too</a>.</p>

<p>And maybe other motives are identified, in the <a href="https://en.wikipedia.org/wiki/Three_poisons#Opposite_wholesome_qualities" rel="nofollow noreferrer">Opposite wholesome qualities</a>:</p>

<blockquote>
  <p>The three wholesome mental factors that are identified as the opposites of the three poisons are:</p>
  
  <ul>
  <li>amoha (non-delusion) or prajna (wisdom)</li>
  <li>alobha (non-attachment) or dāna (generosity)</li>
  <li>adveṣa (non-hatred) or mettā (loving-kindness)</li>
  </ul>
</blockquote>

<p>Also I'm not sure about your premise, that "there is no I" or even than there <em>might</em> be no I.</p>

<p>So far as I understand it, questions about whether the self exists or doesn't exist, will exist, won't exist, used to exist, and so on, lead to a "<a href="https://www.accesstoinsight.org/tipitaka/mn/mn.002.than.html" rel="nofollow noreferrer">thicket of views</a>" and not to liberation:</p>

<blockquote>
  <p>This is how he attends inappropriately: 'Was I in the past? Was I not in the past? What was I in the past? How was I in the past? Having been what, what was I in the past? Shall I be in the future? Shall I not be in the future? What shall I be in the future? How shall I be in the future? Having been what, what shall I be in the future?' Or else he is inwardly perplexed about the immediate present: 'Am I? Am I not? What am I? How am I? Where has this being come from? Where is it bound?'</p>
  
  <p>"As he attends inappropriately in this way, one of six kinds of view arises in him: The view I have a self arises in him as true &amp; established, or the view I have no self... or the view It is precisely by means of self that I perceive self... or the view It is precisely by means of self that I perceive not-self... or the view It is precisely by means of not-self that I perceive self arises in him as true &amp; established, or else he has a view like this: This very self of mine — the knower that is sensitive here &amp; there to the ripening of good &amp; bad actions — is the self of mine that is constant, everlasting, eternal, not subject to change, and will stay just as it is for eternity. This is called a thicket of views, a wilderness of views, a contortion of views, a writhing of views, a fetter of views. Bound by a fetter of views, the uninstructed run-of-the-mill person is not freed from birth, aging, &amp; death, from sorrow, lamentation, pain, distress, &amp; despair. He is not freed, I tell you, from suffering &amp; stress.</p>
</blockquote>

<p>Also, any view-of-self leads to suffering (see <a href="https://buddhism.stackexchange.com/a/15904/254">this answer</a> for details and references) ... and I think that "view of self" includes "I exist" and "I don't exist": these would both be considered self-views.</p>
 -1: <p>Experiances come into being by causes and so does a notion of &quot;I&quot; or &quot;self&quot; (one of the <a href="http://zugangzureinsicht.org/html/tipitaka/an/an03/an03.040.than_en.html" rel="nofollow noreferrer">governing princibles</a>). It's wrong to think that the way to liberation is primaly done by placing the strategy of not-self to it. A good and healthy self-esteem is a fundamental reqirement, and since <a href="http://www.zugangzureinsicht.org/html/tipitaka/kn/ud/ud.5.01.than_en.html" rel="nofollow noreferrer">nothing is more dear to being than one self</a>, it's actually the drive to liberation.</p>
<p>Some very good explainings how to apply certain self and not-self strategies for going beyond all kind of self-views is certainly given in the teachings of: <a href="http://zugangzureinsicht.org/html/lib/authors/thanissaro/selvesnotself_en.html" rel="nofollow noreferrer">Selves &amp; Not-self: The Buddhist Teaching on Anatta</a></p>
<p>Experiment with it and find out by yourself, using the basics, generosity and virtue as guides while walking toward concentation and seeing as it is.</p>
<p>And yes...</p>
<blockquote>
<p><a href="http://www.zugangzureinsicht.org/html/lib/thai/chah/insimpleterms_en.html" rel="nofollow noreferrer">Doing the Math</a></p>
<p>The Dhamma is like doing math. There's multiplication, division, addition, and subtraction. If we can think in this way, we'll be intelligent. We know the right time and place for things. We subtract when we should subtract, multiply when we should multiply, divide when we should divide, add together when we should add together. If we multiply every time, our hearts will die from the burden. In other words, we have no sense of enough. No sense of enough means no sense that we're growing old.</p>
<p>Anyone with a sense of growing old is a person with a sense of enough. When there's enough, the words, &quot;Okay, that's plenty,&quot; can make their way up. If there's not enough, that &quot;okay&quot; can't make its way up because we keep on wanting to take. We've never thrown anything away, let anything go, put anything down. We're always taking. <strong>If we can &quot;okay,&quot; we're at ease</strong>. That's enough.</p>
</blockquote>
<p><em>[Note: This is a gift of Dhamma and not meant for commercial purpose or other low wordily gains by means of trade and exchange.]</em></p>
 8157: <p>When not-self is fully realised there isn't anything to do; apart from to help others realise not-self. That is why the suttas say about the fully enlightened state of mind: "<em>There is nothing further in this world</em>". Because the full realisation of not-self is the supreme liberation or happiness, the fully enlightened person only performs compassionate actions to help others realise not-self. </p>
 151: <p>No matter if we do or do not have a self</p>

<p>The view that we "surely have a self or soul", </p>

<p>drives our desire to propel through life.</p>

<p>We want to be &amp; to do &amp; to exist.</p>

<p>So the goal of the practice is to:</p>

<ul>
<li>let go of the desire to be anything.</li>
<li>let go of the desire to do anything.</li>
<li>let go of the desire not to be anything.</li>
<li>let go of the desire not to do anything.</li>
</ul>
 11541: <p>It is not that you existed and then you ceased to be after learning Buddhism. You never existed. You did no action. Your identity of self was an illusion. If you did not do any anything in the past then will you do anything in the future ? No.
If you did not do anything in the past then will you do anything in the present ? No.</p>

<p>Give up the identity of Self. Give up the desire to be Mr. Somebody. None of the identities are worth identifying as Self.</p>
 13443: <p>It is not that there is no self. There is no self in the way you think of a self. That is, there in nothing inherent in what you refer to as "I".</p>

<p>When you understand this, you free yourself and your actions are able to transcend limits. With this understanding, your actions become perfections.</p>

<p>Which is why everything you do should be with an understanding of selflessness.</p>
 4903: <p>It essentially doesn't change anything. If you look hard, that "I" was always an illusion. No matter where you try to draw a boundary - it is artificial:</p>

<ul>
<li>Does the body belong to the self or not? How about that constant flow of matter and energy in and out - at what point does it even belong to the body?</li>
<li>Do thoughts belong to the self or not? You are hopefully aware how much of your thoughts are triggered by others, or even just repeat outside influences. Often they are even rationalizations of what you just did for other reasons.</li>
<li>Do feelings belong to the self or not? Much of these are determined by past experiences, your situation, even medications, weather, food.</li>
</ul>

<p>So, to keep up this delusion of an "I" separate from the rest of the world requires carefully ignoring all things saying otherwise, which is stressful, even harmful to keep up. If you let that drop away, you'll function as you always did, but with loads of more peace. Don't worry - if this body is hungry it will eat, no matter whether you create such mental complications around that process - or not.</p>
