A doctoral dissertation in 6 seconds

Pete dons his cat costume--ears and tail

Erik: Pete, are you a cat?
Pete: No. I'm wearing a cat costume.

Sometimes a cigar . . .

Scene: dining table, lunchtime.

(Pete begins making little waves with his hand and arms.)

Erik: Pete, is that the tuna fish? (referring to a song he knows)
Pete: No.

(Pete switches to a more overhand wave motion.)

Erik: Oh, are you swimming?
Pete: No.

(Pause)

Erik: What are you doing?
Pete: I'm moving my hand!