You absolutely cannot fathom how seriously he takes this. So seriously. He studies, takes notes, asks thoughtful questions, and goes away to think for a while.

The next time he sees Sans, he will walk up and solemnly present the following for grading.

A: Knock, knock.
S: Who’s there?
A: Eiser.
S: Eiser who?
A: Your eiser glowing in the dark!