A healthy dose of paranoia is absolutely the way to survive on your bike. About the only thing you can trust not to screw you over is a tree. Of course, trees can easily conceal other objects...
I am invisible in my mind when I'm riding. In fact, the one thing that catches me off guard is people yielding when they shouldn't be yielding - drives me crazy, and throws off my game.
Can't stand that. If they'd just gone when they should have, I wouldn't have had to fully stop and unclip. Working on my trackstands, but can only do them for a few seconds still...