I've noticed that sometimes I develop a one-track mind. That can be a good thing in some ways, but most of the time you can't think about anything else until you finally get over it. It'd be great if I could control it, so I could shut just about everything out of my mind for a while and then switch it off so I could function normally. When I get like that, my mind wanders and I end up trying to figure out some pointless problem. Maybe it's ADHD. I think you need more symptoms for that though. I'm not really hyperactive. Anymore. I think of it like having a rocket strapped to your back. Once you light it, you better not have to stop anytime soon, but you can sure get somewhere fast.