https://youtube.com/watch?v=7RMwyqLKyoY [Embed]

This movie is about a family who hides in a bunker because they think there's a nuclear war, and their son grows up in there. The dad explains to him in theory using figurines how to play baseball. But he cannot explain to the son the dynamics of the game and how the players move in action. The son keeps asking "why does he move over there?" and the dad says "because he has to", but the boy does not understand.

Later in the movie they come out from the bunker and he goes to watch a baseball match for the first time. He then expresses "because he has to!" when he finally understands why the players are acting the way they do in the game.

It's this kind of thing.