Explaining Crankshaft

In a sepia tone (indicating a flashback) we see a teenage Ed Crankshaft dozing contentedly. Suddenly he clenches his his and opens his eyes.
"I just remembered I have a test today." he says, angrily.

In the present, Ed sits at the kitchen table, staring grumpily at the cup of coffee before him.
"Are you doing okay?" asks Pam.
"I'm fine..." says Ed. "I just don't like tests."

See, it's funny because Crankshaft is slowly succumbing to age-related dementia, losing track of what's happening, where he is, what year it is, etc. His mind, the thing that makes him the person he is, is gradually disintegrating, leaving him confused and angry and his family helpless and distraught. Comedy.

Comic