It's kind of funny that even in the face of a scientific review done at a prestigious University people do not want to admit they were wrong and the people that told them to do it, were also wrong. It's also ironic that the study to tell people to drink water was probably done at an equally prestigious university :P

Everyone has built up their psuedoevidence for drinking lots of water. They have even convinced themselves so much that there body is starting to somatize symptoms of dehydration!

Since the dawn of human existence we have been using our instinct of thirst to regulate our fluid balance--I see no reason why I shouldn't continue using that theory. When I'm thirsty, I drink. It's amazingly simple and it's prevented kidney failure and stones.

"It is often stated that by the time people are thirsty, they are already dehydrated. On the contrary, thirst begins when the concentration of blood (an accurate indicator of our state of hydration) has risen by less than two percent, whereas most experts would define dehydration as beginning when that concentration has risen by at least five percent." (Valtin, M.D)

Bottled water is my own personal pet peeve. In the United States the tap drinking water is cleaner than the water in bottles and does not taste any different. People just make up the excuse that it tastes bad to legitimize buying bottled water.