I've had lucid dreams since I was a kid. I didn't even know what to call them back then; no one had ever told me they had a name. I got the idea into my head that maybe I could use it to control things and started practicing that, which mostly involved summoning creatures I created (or turning into one) to beat the crap out of stuff in nightmares that scared me. I actually started to look forward to nightmares because of this. It wasn't until years later that I actually heard of what this sort of thing was.