"Where's Alex?" I asked, as I finished applying my daughter Megan's sunscreen. We had just arrived at our town pool, but Alex was out of sight. Then I saw him, his white rash guard swim shirt catching my eye. He was all the way by the pool, about to go in. Jump in. His tan face relaxed and happy, he exuberantly yelled, "CANNONBALL!" as he splashed into the water. He came up, laughing, wiping away the water from his eyes, then diving under again. Sure, I'd seen him improve a lot in his private swim lessons, but those were one on one with an instructor and a pool full of children with their instructors. This was a whole new situation- where he was applying his learning independently and joyfully, without any scaffolding or support. I thought back to last summer, when we took a family trip to the suburbs of Chicago to visit my husband's brother and his family. They had a lovely pool for the children to swim, but Alex was petrified. He stood ...