She made an extremely valid point, but she hadn't yet interacted with him when he was acting what most considered normal. He wasn't completely changed but he was certainly less of an obvious bully and more of an ass in general, something he still didn't quite like about himself. It was in meeting people like Susan that had him wishing he wasn't so prone to his kind of behavior.
He was, in short, jealous of easy it came to her to be kind and approachable not just because she was pretty or talented, though that didn't hurt either.
He rubbed his chin.
"I did stupid things as a kid," he admitted slowly. "I don't think I remember half the shit I used to say or do... for the most part I wouldn't say much of my tastes have changed either, not fully. I mean... merlin, I'm not a nice guy. I don't usually save the day and I don't usually have girls over for tea if you kn- fuck, I mean.."
He wasn't very good with words and it was this that made him feel stupid and angry. But not at her, so he took a moment to think about what he meant to say and leaned forward a bit to speak to her as if he were sharing a secret.
"I'm really not a good person, but sometimes being... being that way all the bloody time seems to get me shit company and it doesn't even matter, in the end, you know? I mean, I could be going blind with what's wrong with my eyes and no more Quidditch and that's all I fucking got is Quidditch and the fame. It's all ruddy and useless, isn't it?"