Let's say you are a 150 pound man who is very active, you may very well need more than 75 ounces of water. Let's say you are a 300 pound man who sits on his ass all day, 150 ounces of water is a lot and will just flush out of you while pissing. So I have always side-eyed that a bit.

I try to drink three liters of water a day, four when I am real active. I go through spurts where I will lift four times a week and hoop almost every day, then I will drink shitloads of water, probably four liters a day and sometimes more. When I end up working a lot and can't do nearly as much, I will cut it to two liters minimum, three if I can.