Deception.

You are wrong if you were to assume that someone who survived hardships are always strong.
They, too, might have endured so much pain, problems, difficulties.
Some might have brought them tears.
But they chose not to show them.

You are wrong if you were to assume that someone who seems to be bright are always content.
They, too, might have endured so much sadness and darkness.
Some might have brought them despair.
But they chose to laugh at them and at themselves.

Because when all hopes are lost, the only way to survive is detach oneself from all sorts of feelings, and choose to pretend to be happy instead.