DaVinci and Kramer only needed an hour a night.

JERRY: Catnap?

KRAMER: No, no, no, no. (comes in) This is evolutionary. I been reading this
book, on Leonardo de Vinci. See, that means 'from Vinci', d'you know that?

JERRY: (deadpan) That must be some book.

KRAMER: Yeah, well, turns out that the master slept only twenty minutes every
three hours. Now, that works out to two and a half extra days, that I'm awake
per week, every week. Which means, if I live to be eighty, I will have lived
the equivalent of a hundred and five years.

JERRY: Just imagine how much more you'll accomplish.

KRAMER: Oh, I got a lot of things in the hopper, buddy.

Kramer heads for the door.

JERRY: I didn't know you had a hopper.

KRAMER: (smiling) Oh, I got a hopper. A big hopper.