Man always forgets his past and present and looks for a future which he is not assured of; wasting even the little enjoyment that he is left with at present thinking that he has to do a lot to make his life after death to be a happy and everlasting one. That's an unknown zone altogether! Nobody knows what it's like! Being in womb is like being in an unknown zone where everything is provided without grafting; living in world is a known zone where you experience happiness and sorrows; but looking for a life after death is again an unknown which man is not assured of. Hence he should lead his worldly life a better one for him as well as well as for others.
Ben