I've thought about it a couple times as I ride my bike on fast, busy two-lane highways, but really don't fret about it. For what it's worth, I could very possibly die in my sleep from a handful of causes or slip in the shower and hit my head just right. We all take risks in the everyday things we do. Although, it does makes one think twice whether wearing a helmet, hi-viz clothing and having bright lights are really worth it as what good is being seen if the driver of the car that hits you is intoxicated or asleep?
I know I'm not invincible, I simply live each day as if it were my last.