I've been thinking about living in a different country for a while. Done it a couple of times for short periods (up to three months), but maybe I should spend a year or so doing something entirely different in a foreign country. Thanks for the advice! I speak a couple of languages, though only 3 fluently, which means that there's a lot more to learn, thanks!
Yes, this is indeed what I originally planned to do. Although I keep a book with the problems / ideas I have, none of them really motivates me (and I think there are about a hundred ideas in there). Given that there are enough ideas, I don't think the ideas are the problem...
I guess this is the perfect solution, but I don't feel like doing that now. I have the time, some money, lots of contacts and no car, expensive house or girlfriend. I have the ambition to become wildly successful. I've spend the last 5 years reading a lot on startups, but I don't see myself putting in long hours of software development at this moment.
It was just a lot of fun. I couldn't help myself. I started my first year of college doing something related to CS, but after I started taking some CS courses I switched almost immediately. My MSc. was even more fun, I really liked the problems. However, I didn't want to go to grad school, I just don't see myself working on one specific problem for 4 years or more.
I guess I'm burnt out indeed. A while ago, I asked my doctor about this, but she said that I should just make a list of things I like to do, and not worry too much: it's natural at my age (the infamous quarter-life crisis).
This weekend I'll leave on a month-long vacation with no laptop, iPad and wireless internet, so let's see if that helps a bit.
Thanks (and also, thanks to everybody else in this thread, I've already learned a lot).