Looking more deeply and understanding helps in knowing better.
Sadness as a feeling is not anything real but the absence of happiness. We feel sad when the reality is not in alignment with our expected thoughts. We fail to understand as to why something did not work out as it should have.
We are so programmed that we get over it and realign with the new reality. That is how human beings are and this can be validated with every other human being living on this planet.
The feeling of sadness is a state that is not acceptable to a human being. Naturally he comes over it whatever be the gravity of the situation.
If he does not understand the logic behind the same the sadness continuous to exist in a subdued state. The feeling flares up whenever it is retrieved from the memory error due to external circumstances or internal thoughts.
If we analyse the reasons a little more and understand the logic behind the incident and our inquisitiveness is quenched then we do away with the sadness permanently.
This is a simple exercise which everyone of us can try and see if it works.
Understanding the human being has been a neglected field of study and knowing the science of a human being his existence on earth and how he can coexist with everything else is what I am studying and continuing to write on.