When You're raised by the half of your family who doesn't give two shits about magic, it's a bit hard to learn magic. He can only do basic magic with vague concepts because he's not very imaginative and struggles with the idea of adding or removing things from his own body. He's already himself after all. I'm sure he could if someone taught him.
(If ya can't tell, I didn't send this ask to him. He still doesn't know.)