どちらが先か－ジョーク分かりと、頭いいのと。
分かってくると、頭がさえてきて、頭さえてくるとジョークもますます分かる、と言えるのか。

以下、日本語はわたし訳－
Sign：道路標識：サイン＞
The teacher says, “Why are you late, Joseph?”
Joseph replies, “Because of a sign down the road.”
The teacher says, “What does a sign have to do with you being late?”
Joseph replies, “