When I'm on the bike, I try to empty my mind of distractions and focus on the ride. For the most part I'm pretty good at it; obviously I still need some work, but the majority of the time I'm riding I'm not paying much attention to anything but the ride. I feel this is a pretty important thing to minimize risk.
But occasionally I'm ambushed by some really sticky thought; something important I forgot to do, or a complicated problem at work, or whatever, and I can't for the life of me get it out of my head. I can push it away briefly, but it always seems to come crawling back. I really don't feel comfortable when I'm distracted like that; I know my reflexes are pretty good, and my instincts are right more often than not, but I'd rather not trust my safety on two wheels entirely to them.
This mental focus is something that still needs my attention.