Actually turns out I was right. I rewatched it again and apparently you're supposed to drink water so you don't get thirsty. If your thirsty, it's basically too late or something. Still a good meme.
DRINKING 8 CUPS OF WATER A DAY; DRINKING WATER FREQUENTLY AND DURING EXERCISE; DRINKING WATER WHEN YOUR THIRSTY; DRINKING 8 GALLONS OF WATER AT ONCE AT 3:00 AM