So by saying he's a boy, it's insulting his theatrics, basically like saying, "Oh, that's nice. Look at your kiddie toys. Now step back and let the real men take over."
"Nice makeup. Was that supposed to make you look scary? You look like a dork."
Dumbledore: "Now, it's great that you've been saving the school and all Harry, but unfortunately your grades have been a tad low, and, well... perhaps Gandalf could explain it better... hit it, Gandalf!
Don't say you don't have enough time. You have exactly the same number of hours per day that were given to Helen Keller, Pasteur, Michaelangelo, Mother Teresa, Leonardo da Vinci, Thomas Jefferson, and Albert Einstein. — H. Jackson Brown