I’m not depressed (at the moment, well maybe a little), just feeling philosophical.
Edit: the idea of this came to me because I was pondering why people fight so hard to beat diseases and live a few more years. What are they planning to do? Why exert effort just to be here longer when you don’t have a reason?
Just why?
Lots of good answers here. You might want to read up on Existentialism, a line of philosophy grappling with exactly this problem. https://en.wikipedia.org/wiki/Existentialism