This is why humans feel sad more often

We humans always tend to feel sad very often.
The main reason is as follows.
Everyone of us like to being cared by someone and to get a caring response from someone,sadness is the best way.
Many of us dont know this as it is made default in our physiology.
For example,consider a small child who was beaten by his parents.
Even after a longtime,if you console them,they will cry.
This is the first sign of human in need of sympathy.
This is what even we,elders do just more or less in a different manner.

ACTUALLY WE TEND TO BE IN SADNESS RATHER THAN TO BE IN HAPPINESS
Confused????
Well let me illustrate with a small example.
If you have succeeded in doing something,how many days you will celebrate???
1 day,2 days,1 week.I bet it could not be morethan a week.
But what is the case if you have lost something or someone important in your life???
That sadness will persist even for years and sometimes even for the life time.
Everyone of us are of the same kind and no one is exemption
.
There is absolutely no solution for this as it is fixed default