The other day, a friend made a confession in hushed tones with sideways glances. "Yesterday I was driving," she said, "and randomly thought, 'Wow, I could just turn the steering wheel a few inches and I would flip into that ditch and die.' It freaked me out and I haven't driven since. Am I going crazy?"
On the contrary, the fact that she did not turn the steering wheel, despite having the thought, and is around to tell the tale, means she's perfectly normal.