My wife said, 'Can you take the kids to the park?' I said, 'Sure.' I took the kids to the park. My son got on the swing and said, 'Dad, push me.' I pushed him. He said, 'Dad, why is the swing not going as high as I want it to go?' I said, 'You have to push it yourself.' He said, 'I'm pushing it.' I said, 'You're pushing it at a 45-degree angle. You need to push it forward, in the direction of the swing's arc.'