He'd rather be a superhero than a dentist. Did you know that college is where you choose what you want to be? You can choose what you want - a doctor, a dentist, a superhero - and then they give you sticker so they know what you chose. When you're done, you're a superhero!
Plus, he knows a lot about superheroes. He doesn't really know a lot about girl superheroes, though. Like Wonder Woman is a girl superhero. (Maybe he could learn about them when he's at college?) No, he doesn't really like the girl superheroes as much. Did you know that boys really like the boy superheroes, and girls really like the girl superheroes. He'll just be a boy superhero.