Do you have three minutes? Then watch this video and afterward ask yourself a simple question. The video is about Tommy Carroll. Tommy’s a skateboarder. A good skateboarder. Which means he’s got great balance, and loves a little risk, and falls down from time to time, only to get back up and skate some more. In all these ways, Tommy’s not that unusual from a lot of other kids who love to skateboard. But though Tommy’s been skateboarding since he was ten, he’s been blind since he was two. Yeah. Tommy skateboards by sound. But while that makes him unusual, I’m still not sure that’s what sets him apart. Because I think what makes...