The "if I knew now..." thing is a bastard.
I used to always think about it in terms of going all the way back to say 17 years old, that'd be perfect. But now I'd take any number of years. 5 , 10. Even though things are crappy (and even that long ago were crappy) I feel like I'm just at the tip of figuring a lot of things out.... and now I'm old... and already screwed up too bad to matter. Even if I do fix everything I'll be old and near dead by the time I get it all fixed.
Oh that was cheerful. So much for my perpetual self-help reading. lol
There is the other end though, they are making huge scientific advances at a faster and faster rate (thus making things for us 'rich' cry baby countries cheaper and safer (despite all our crying), maybe they'll figure something out for longer life and cheaper ... everything (Cold Fusion / Uber Safe Nuclear and Gene (DNA) Therapy) being close to 1. Very much cheaper everything 2. Kick ass medicine. So maybe if we live LONG enough...