I've always asked myself that childhood in humans last up to 18 to 22 years, but in our closest relative, the chimpanzee, childhood lasts just 8 years. And so you wonder why that is. Well, you can blame it on this.This is a brain cell. It is called a neuron. This is not a brain cell.This is me when I was 3 months old. Yes, I wasn't thinking that I was going to give a TED talk anytime soon, but I had a lot on my mind. At least I had a lot of neurons on my mind about 90 billion of them.And we're going to come ...