I know what you mean about the anesthetic, Steve, cuz it's always a non-zero risk. I just tell myself that I take a bigger risk every time I drive my car or cross the street.

In either case, it's not like there's no logical reason to worry at all, but if you let yourself focus on those possible-but-unlikely events and worry about them, you can paralyze yourself into not living. You have to just choose to let it go. You can do it about driving, you can do it about anesthesia.