 mammals need to play. They need to play physically. It's especially clear for boys. Boys need a lot of rough and tumble play, wrestling, running around. All kids do. And that's what our brains are kind of expecting. And we need to develop our social skills one-on-one or in small groups. You say something, your friend makes fun of you, you're a little embarrassed, and then it's over. You move on. So that's a healthy childhood. You have to make a lot of mistakes, and they have to be low-cost mistakes. We all made thousands of low-cost mistakes, and we learned from them.