Here’s our payoff- Marty doesn’t get hangovers because he sleeps through them.
It’s just a short little page to wrap up the act. My earlier note about the watch should come into play here- Marty is not the kind of guy who owns a watch that shows the time at all times. It has to be a calculator first, with a TIME button. It may be that it only shows the time while the button is being actively pressed. Owning and wearing one of these is how you can prove to the world that you are cool.
There is no other way.
