Quite a while back, my sister-in-law posted on her blog that her son, George, had walked in the door from church, gotten himself a yogurt, and ate it without spilling a drop. George is only 20 days younger than Big, but Big often forgets that fact because he's bigger than his cousin. And, when you're 3, the concept of time can be just a tad elusive.
Yesterday, Big was eating a yogurt and making a terrible mess because he wasn't staying focused on his task. I pointed out to him that his cousin can eat a yogurt without spilling, so I know that he can, too. Big seemed shocked and a bit dubious at the revelation.
Then this morning, after clearly having mulled it over all night, Big said, "George is 2 years younger than me, and I'm, like, 3 years older than him... so how is it that he can eat a yogurt without spilling?"
When I told him that no matter how sketchy the math the answer is still the same, he seemed disappointed. You just need to pay attention to what you're doing, Big.