water intake

How much water are you told to drink at your doctor appointments? Every time I'm asked how much water I drink, I tell them 2-3 water bottles. 16 oz water bottles.. they tell me I should be drinking 8-10 of those... in my opinion that's freakin insane. Nobody drinks that much water. I can't possibly drink that much even if I tried. The most I can get in one day is 4. I always heard it's supposed to be 8 oz glasses of water. A 16 oz bottle of water is two 8 oz glasses. So I'm sure I'm getting enough water.