user17744: Today I realize that, if something good or bad happens to me, it is caused by Karma. It gave me a huge relief. Because before I would experience aversion when something bad happened to me. But now, I believe that I am 100% responsible for whatever happens to me.
But, As I know, not everything is caused by Karma. There are some other reasons such as whether, Dhamma etc. So how can I know the real cause behind something for sure? (Is it Karma or some other cause?)
It is said that someone needs to experience the truth to understand the truth. So how can I build a solid understanding of the cause behind things and Karma?

user471: Yes. It's true that not everything is caused by karma. Some things are caused by other reasons, like the weather. The Sivaka Sutta talks about this. There's a summary at the bottom:

Bile, phlegm, and also wind,
  Imbalance and climate too,
  Carelessness and assault,
  With kamma result as the eighth.

The Acintita Sutta states that you can't work out karma and its results precisely:

"The [precise working out of the] results of kamma is an
  unconjecturable that is not to be conjectured about, that would bring
  madness & vexation to anyone who conjectured about it.

What's more skillful is to develop one's virtue (sila), concentration (samadhi) and wisdom (pañña) as stated in the Lonaphala Sutta. That will mitigate the ill effects of past karma.

17744: <p>Today I realize that, if something good or bad happens to me, it is caused by Karma. It gave me a huge relief. Because before I would experience aversion when something bad happened to me. But now, I believe that I am 100% responsible for whatever happens to me.</p>
<p>But, As I know, not everything is caused by Karma. There are some other reasons such as whether, Dhamma etc. So how can I know the real cause behind something for sure? (Is it Karma or some other cause?)</p>
<p>It is said that someone needs to experience the truth to understand the truth. So how can I build a solid understanding of the cause behind things and Karma?</p>
 471: <p>Yes. It's true that not everything is caused by karma. Some things are caused by other reasons, like the weather. The <a href="https://suttacentral.net/sn36.21/en/bodhi" rel="nofollow noreferrer">Sivaka Sutta</a> talks about this. There's a summary at the bottom:</p>

<blockquote>
  <p>Bile, phlegm, and also wind,<br>
  Imbalance and climate too,<br>
  Carelessness and assault,<br>
  With kamma result as the eighth.</p>
</blockquote>

<p>The <a href="https://www.accesstoinsight.org/tipitaka/an/an04/an04.077.than.html" rel="nofollow noreferrer">Acintita Sutta</a> states that you can't work out karma and its results precisely:</p>

<blockquote>
  <p>"The [precise working out of the] results of kamma is an
  unconjecturable that is not to be conjectured about, that would bring
  madness &amp; vexation to anyone who conjectured about it.</p>
</blockquote>

<p>What's more skillful is to develop one's <a href="https://www.accesstoinsight.org/ptf/dhamma/sila/index.html" rel="nofollow noreferrer">virtue (<em>sila</em>)</a>, concentration (<em>samadhi</em>) and wisdom (<em>pañña</em>) as stated in the <a href="https://www.accesstoinsight.org/tipitaka/an/an03/an03.099.than.html" rel="nofollow noreferrer">Lonaphala Sutta</a>. That will mitigate the ill effects of past karma.</p>
