Well, I do comprehend the fact that I won't wake up. I just don't... I don't think there's a word for it. It's kind of like with space: I understand
that space is infinite, but
infinity itself escapes my grasp. Things must have a beginning and an end, otherwise the human brain just gets all dizzy and goes "Dude, like, far out, man.".

At least mine does... It's said that one can indeed 'grok' infinity, but only in a mystical/drug experience, temporarily. Certainly a mystical experience would help to alleviate my fear of death, even if it was all hooey in the end.