What should we do with our lives?

Evidently, we exist for whatever reason. Life is short, we die, probably cease to exist forever.

During the short period that we exist, what is the best use of our time? Studying mathematics or science? Contemplating and philosophizing? Working in a field that is focused on life extension/immortality?

What do you guys think,? And do you think someone sitting away in their room playing vidya all day or someone only participating in hedonistic activities is wrong, inferior, or the strain on society? Would you look down upon them?