Have been doings tons and tons of side-projects hoping them to fly. I will tell you a story. When I was in college, I got an offer from Cambridge University for paid internship (800 pounds per month + travel -- that's a lot for a student). But I was so enthusiastic about startups (thanks to HN!) that I declined that offer and started a so-called startup of recruiting people through social networks. We had a fancy tag-line "infiltrating social networks' and I distinctly remember having day-dreams of dominating the recruiting space with that idea. Needless to say, two months of summer and lot of naivety doesn't translate into success.

No, I don't regret having dropped Cambridge Univ. internship for a failed startup because at that time it seemed perfectly rational thing to do. I'm happy about the lessons I learnt from that stint and it made for a great groundwork for my future startups.