Dave the Geek
“Yeah sure, take the shotgun if you want, I’ll take the... AMMONIUM... NITRATE!”
As far as he remembers, Dave always found reality to be terribly boring. So he locked himself up in an imaginary world and learned piles of useless stuff... useless until now. Dave is a fount of knowledge. His chemistry mastery makes him look like a superhero amongst other survivors. At least until he opens this mouth, then everyone remembers he’s a real geek.