LOL! I know what you mean. I'm usually on red alert when riding... I monitor what's behind me and plan an escape in case I get bum-rushed by a car... at the same time I monitor cars parked to my right and anticipate that one of them may pull out at any time and how I should respond... also look for debris in the road as far as I can see. I'm constantly scanning my surroundings and anticipating the worst and what my reaction would be. Yet a few years ago I was on an unfamiliar MUP going at a pretty good clip. It was early in the morning so nobody was around. I let my guard down and had my head in the clouds until I realized that the path I was on was about to follow a couple of dozen concrete steps to the path below. I went airborne. I was lucky to have been wearing a loaded back pack that cushioned my back when it hit the concrete steps midway down. A couple of scrapes was all I got... I was lucky. I mounted my bike and continued to ride but went back into red alert mode from that point on.

Your chances of avoiding accidents is increased if you stay alert but all that is needed is a momentary lapse to get bitten.