I love people-watching at the grocery store. Possible I need to get out of the house more, but it is a source of amusement nonetheless. Today, a father and son were in the frozen food aisle. The kid was probably 3-ish, and having outgrown the seat, he was sitting in the main part of the cart. All was going well, with the kid experimenting with the laws of physics that enabled him to scoot the cart by shifting his body weight around. Then he discovered the hinged panel that allows the carts to nest together. At first, he told his dad it was loose, and dad him that his "cage was broken." Then the kid discovered that it lifted all the way up.
So much for containment.