### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
I am in my 40s.  I have, since childhood, suffered from periods of relatively sudden (sometimes magnified by a bad situation) periods of sadness.  My symptoms are feelings of despair and the urge to express sadness (crying, isolating myself, etc.) that sometimes seem to occur without cause.  These episodes are sometimes crippling for short periods of time.  I also seem to take on other peoples feeling of sadness.  I am not comfortable watching new events about tragedies and funerals are an absolute no go whether I know the deceased or not.  During my late teens and 20s, I was able to self fix or correct the issues almost immediately.  I seem to have lost that ability.  My question is this...  I have met or had in my life, certain people that, for the periods of time that I associate with them, whether at that time I am in direct contact with them or not, seem to eliminate all (all!!) of my issues.  During these time (most recently a two+ year period) I have no memorable episodes.  The people that I have experienced this with in my lifetime are few (maybe 3 or 4).  Sometimes it was immediately obvious and sometimes it didnt occur to me until much later or until after that person was no longer part of my world.  I  know it is possible for a single person to have this effect on me.  Is there an explanation for this?I am very social and outgoing.  I am well educated, and have some basic artistic talents (writing and drawing). I enjoy a wide range of activities.

### output:

Degree understand your concerns went through your details. I can understand your emotions. We have three types of memory. Sensory memory, short term and long term memory. Sensory memory is for seconds. Short term is for minutes. Long term from minutes to years. Yet, there is nothing which is super long term. So many people forget memorable episodes. So many remember experiences which are not worth remembering. Selection is the key. Selection purely depends on perception and experience. Having explained all these, now you should venture into understanding memory procedure and process. Then you will get the answer to your question. For sure, you do not have any memory problems which need medical attention. Take care. If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute details possible. Hope this answers your query. Available for further clarifications. Good luck.