Week ago, on the last warm autumn afternoon, Mark and I walked along the river. Eventually, we arrived at Telulah park. People played disc golf, families communed, and kids embraced the skate park. One kid waited patiently, then took a turn: skateboard revved, onto the downhill, up the curved side, and then his moment, an attempted trick, which left him on the ground. He stood up, walked away, and waited for his next turn.