I have two little cousins. One of them was the sweetest, cutest, quietest kid ever. The other one was a crazy brat who liked to claw at my arms and pour the contents of his potty training pee bucket all over the floor.
The sweet one grew up to be a spoiled, conniving, evil monster. The crazy one is the sweetest little jokester in the world, and loves to bring food to you and offer it politely out of affection.
Kids are weird, weird things.