The most exciting moment for Ethan during our visit to the Children’s Museum on Navy Pier was the instant he saw the wheel loader. He could see that he’d be able to climb right in. Thanks to a NATO convention in the city that kept most people home, there wasn’t any waiting. But that only kept his exuberance all the more brief, for as soon as Ethan discovered that none of the controls did anything and that neither the wheel loader nor its scoop were going anywhere, the exhibit immediately shifted from fascinating to entirely disappointing.