Because I Have To
I am a cold, hard pragmatist. (I hear you laughing; bear with me.) My advice for a long and happy life would be roughly ‘don't think too much, and don't make things more complicated than they need to be.’ (Your laughter is growing.)
Seriously, I do my best to follow my own advice. It's all about defining your terms. Easiest first: I think I make things only as complicated as they need to be, it's just that that proves to be still quite complicated. Which makes sense. We're all quite complicated people.
If I'm honest, I think a little too much. I'd define ‘too much’ as the point where you stop seeing results; where the thinking is no longer making your life better. Most of my thinking, though, most of it, still gets me results. And in the last couple of years I've managed to greatly reduce the amount of completely useless spinning-in-a-loop second-guessing that I used to do, so that's something.
I wouldn't recommend anyone copy my approach to life. It's a lot of work, and it is quite complicated. But the point is that it's necessarily complex, and it's working pretty wonderfully for me. Sure, I can't manage a real job, or a conventional faith, or (maybe) monogamy — if I could, I probably would. But I live the only way I'm able to live.