User blog comment:Leanilla/Who's Cuter? Phineas? or Ferb?/@comment-2183263-20100723145539

Actuall they're both smart, except Ferb uses his more because Phineas is naive to some things. Like when he thought Perry layed an egg, he didn't stop to think about Perry being a guy. I guess he took the "they're the only mammals to lay egg" thing too literally.