Water is good and more up to a point is better. But there are a lot of metrics like a gallon/day that should be examined. For instance, aiming for 2% inflation seems good but there is no science behind it. The 2 percent rule started out in New Zealand as a wet finger in the breeze by government officials. Same with 10,000 steps/day. That comes to us from a 1960's era marketing campaign by a Japanese company selling pedometers. No science at all, just a nice round number. Later investigation by scientists says the sweet spot for steps is 5000 to 7500/day, beyond that? No benefit. So before you sign up for any of these rules of thumb consider your situation. How talle you? How much do you weigh? What's the ratio of the weight of water to your body mass?