"I keep hearing grown-ups say that kids are resilient. I don't really know what that means. Does that mean I'm supposed to be OK? I can try to be OK. But I'm not, really." One day Gavin was a pretty typical 8-year-old boy. He loved his friends, going to school, playing baseball, and watching YouTube. And then the whole world changed. Some of the changes were sudden and dramatic due to COVID. Some of the changes were gradual and...