I don't ever get thirsty, I am in Texas and I have trained myself to drink. But if I am doing something hours upon hours could pass before I drink. I just have no urge for drinking. I exclusively only drink water, but I just don't have the urge to drink. It's been like this forever.

I visit the doctor quite frequently and he says even though I and other people have this, I am pretty healthy. So that's a plus. :).