You're over there in the corner either thinking about the dead dog or whatever, you're bringing up your personal life and you need the space, and then somebody throws you a joke. Especially if it's an emotional scene, you don't want the joke.
Honestly, I was a good kid but I figured out pretty early that I had a gift for making people laugh. I wanted to entertain and when that happens you tend to get yourself in trouble in class.
A lot of directors are great and they are fine but you know I think that Harry really takes a special point to really engage the actors and really make it feel like a safe place for them to explore whatever it is they want to explore in whatever scene with their character.