Look 18, but be 80 years of age. I mean, fuck it, that's like what? 2-3 more years until I've passed?
Would you rather be forced to survive in a hellish post-nuclear war world, where food is scarce and you're always under threat by bands of marauders and mutated creatures who will commit unspeakable things to you if they get a hold on you? You're no hero in this world, just some random person. You're free to do what you want though, other than kill yourself.
Or would you rather survive in a small underground bunker that holds enough resources and amenities for you to survive for the next 10 years, but has no forms of entertainment aside from some old crossword and sodoku puzzles, and you won't be able to connect to the outside world or ever leave it? You'll only die once your resources run out.