I dropped out of university about 7 years ago ... was in the process of writing up my masters thesis in marine parasitology, but as I had long suspected, my data had been borked by other people, and there was nothing I could do about it, so I just junked it all and walked out. Can't say for sure where I wanted to go with it all ... for me life is all about learning and discovering new things, so I would have done anything I could to stay on at uni and continue doing research. Maybe take on a teaching job or something while doing my doc and then post doc.
My career as a zoologist was dealt a mortal blow when I taught myself to program soon afterwards, and found it much more rewarding to do that. Every once in a while I get really annoyed with the usual crap that's inherent to working as a programmer (managers, poorly-defined spec, constant requirement shift etc), but then I find a better job or learn something new, and that keeps me going.
I'm a very firm believer in not planning life, because there isn't really a final destination. If there was, you'd be able to "win" life, and there'd be high scores too. Nope, as long as I'm doing what I find interesting, and can pay rent in the process, I'm happy. I'd love to get my Masters some day ... some day. What I do after that is just another step towards another step.