I thought I was ready to die at 19. Turns out I wasn't, I was just depressed. I turned things around, and most of the things I've done that make my life meaningful to others took place after that. So if I had died when I thought I was ready, my life would have been pointless. I would have never amounted to anything other than a parasite who consumed (food, money, time, people's emotional energy) and gave nothing back.
People are often terrible judges of what the scope of our lives is because our point of view is so limited. That's why I think the best attitude is to be ready to die (as in prepared to accept that possibility and aware of your own mortality) but to fight to stay alive as long as is ethically supportable, and in the mean time live so that your life is of value to others.
Just in case someone is going to try and turn this into a euthanasia discussion, I'm not saying people can't choose to die when they want to or that we should have a law against it or anything so mundane.
I'm just saying that from everything we know about the cosmos, life is fantastically rare. Life which is intelligent enough to have a self-identity it is consciously able to distinguish from other intelligences is even rarer- it may be down to us and like 5 other species. Life which has the exact same consciousness and experiences and identities as you- well, that's pretty much down to just you. In all of the estimated 160 billion light years of the estimated universe [http://htwins.net/scale2/], in the entire ~14 billion year history of the universe and the possible trillion years the universe is expected to continue before its destruction, there will never be another entity with the same experiences and consciousness of you[footnote]until/unless someone develops/d brain duplication on a quantum level[/footnote]. The typical notion of human value is something along the lines of value = 1/rarity * utility, the rarer something is and the more useful something is, the more valuable it is. You are infinitely rare, so as long as your utility is > 0 (you contribute something of value to anyone around you) you are infinitely valuable.
The thing is, people rarely understand what they contribute to people around them, so I think its very bad to just be cavalier with one's life. I can understand deciding not to live longer if someone has a painful terminal disease or is in such an advanced state of age that they can't see themselves ever being anything but a burden on others (I don't agree with it, but I understand it). But to die simply because one is ready to die? That sounds profoundly wasteful to me, like the people that put gold flakes on their food instead of using that gold to make something of value that can be enjoyed by everyone.
