This interview with William F. Buckley, which I saw as part of the Best of Enemies movie about his adversarial relationship with Gore Vidal, really left an impression with me. That it is possible to reach a point in life where you're so tired, so out of ideas, that you wouldn't go back and do it again.
Here's the beginning of the interview.
Rose: Do you wish you were 20?
Buckley: No. Absolutely not. No. If I had a pill that would reduce my age by 25 years I wouldn't take it.
Rose: Why not?
Buckley: Because I'm tired of life.
I go back and forth on this. There are a lot of things I'd like to do that I'm pretty sure I won't get to do. I am disappointed in the way the most important things to me turned out. I also am tired of life. But I have moments when I'm not. I think you can see that in Buckley too.
I think as you get older you have a bit of Bowie and a bit of Buckley. You go back and forth. I think eventually, if you live long enough you do get tired of life, the repetition, the roles we're expected to play, whether they fit or not. The endless arguments that never get resolved. The pointless will of human beings.
PS: If someone offered me a pill that would make me 20, I'd take it. ;-)