Thinking about answering this made me feel better about myself than I have for a while, so thanks for that. I just realised that I've already done a lot of the things I always wanted to do, and way earlier than I ever imagined.
I always wanted to own my own yacht and sail it around the world, but I pictured that happening (if ever) when I was around 45 or even after I retired. Well, I still have a couple of years of payments to go before I technically *own* it, but I bought my dream boat (a 30 foot, 30 year old sloop) a couple of years ago when I was 27, in spite of being told by the entire world that I was insane. I'm only a couple more years of experience away from being able to do the big trip, too. The boat's been round the world once before, without me, so I guess she'll stand up to it again with me some day.
Most of the things I wanted to do when I was a kid involved adventurous, exciting stuff like being a 19th century explorer. I was always angry that it seemed everything had been discovered and all the mysteries were solved before I had a chance - born too soon to explore in an intergalactic spaceship, too late for everything else. I still wish for mysteries and exotic quests, but have come to realise that there's enough here in the world that *I* haven't seen, even if other people have, so I should just quit complaining, go off and darn well discover it anyway. And have fun. That's what I'm doing now, so I guess I'm doing all right.

Brunnen-"I want a time machine"G