Before I read this book, I thought I had a working idea of what autism was. I didn’t. Now, I think, I do. Higashida, who wrote this when he was 13, tells us something we don’t normally hear — what it feels like to be autistic. “It’s troubled me for quite a while that I can’t laugh along when everyone else is laughing,” he writes. He says his sense of humour is different. “If we’re surprised, or feel tense, or embarrassed, we just freeze up and become unable to show any emotion whatsoever.” The introduction, by the novelist David Mitchell, who has an autistic child, is excellent.