I agree with 5kg that high water intake is oversold in general and that it was intended to include all sources....forcing water is not better.
Soldier is also right...the point for most people newly engaging in a healthier routine is to drink more than you were....it's good for so many body processes, removing toxins, etc. but once you find level health, you only need what you need....at one point I was drinking one pint of pure water per day with no ill effects...i was also drinking almost a gallon of milk...I was plenty hydrated.
Was Soldier right in your case? Are you drinking other than water most of the time?
"You must have a very strong reason for doing an exercise. If you don't, scrap it and move on." -Jim Wendler