Our kids' school had a friendly soccer game recently. The kids' teacher played goalkeeper, and had our 4 year old J tag along with her in goal. After observing for a little bit, J figured he knew a better way to help his team. Finding some large-ish stones, he piled them into a small wall across the face of the goal. The teacher was perplexed, but he explained that this would help keep the other side from scoring. (Seems much more efficient to me than her method!) After a few minutes, the sagacity of J's idea was confirmed. A ball beat the keeper and was rolling in for a goal, when it was stopped by his little wall. 'No Goal!' he cried with glee. His teamates cruelly undercut him by deciding that the goal ought to count.