I'm a person just like you, I have dozens of side-projects around. The difference is that I've never went "far" enough to buy domains for any of those.

But I have a decent half-baked AI based investment portfolio manager, one month of hard work (nights/weekends) dreaming of selling it for a bank. Projects of such complexity are impossible for people stuck in the ordinary life (job/family). PS: I'm not complaining - I love my family. But it demands energy.