If you like to pee a lot, then 8 glasses a day is fine. :) Actually, no one knows where the mythical "8 glasses a day" came from, but I seriously doubt any well-educated doctor will tell you that. Your body has an exquisite system of organs and hormonal controls to regulate the amount of water in your body. It is also able to extract a great deal of water from the food you ingest every day. If your body needs water, your thirst will increase automatically. Just pay attention to what your body is telling you instead of counting an artificial number of glasses of water.