BTW, does this only happen to me? You're reading something, you say "hey, that looks to be an interesting niche" and next thing you know, you're up half the night researching and registering...
Constantly happens. I don't spend half the night looking into it though. Keyword research, competition analysis, "do i really want to do this site?", and boom I pull the trigger.
I own more domains than I know what to do with... probably the same as everyone here. Some of them were before i knew how to do proper keyword research too.