Too much sugar would have been a good excuse, but in reality this was just how he was: hyper, excitable, pleased. Except for when he wasn't, and then he was the terrible exact opposite of that. But he didn't like that - didn't like himself when he got like that. So he just tried not to be.
"I like a party," he said, as if that were the topic at hand. "Or just ice cream." Hey, he was easy.