I hope Oscar doesn't become a grouch
I think the sipping is so you don't overstrain the pouch. Even too much water can fill up and put pressure on a small opening, most likely making you naseous. Ever guzzle too much water when you were a kid, so you sloshed? A bit nauseating.
Oh, I found a great help. Propel makes a vitamin water bottle that has a great "sipping" top. Twist it open and closed, and I can stick it in my big purse and carry it anywhere.
Hope you're feeling better and better!