Why do I struggle to drink water?

This is a rather baffling concept to me, even as I experience it. We all need water to survive. So far, I've succeeded in drinking enough water that I don't keel over and die. (Which is about 1-2 cups a day. Horrific.) But maintaining an optimal level of water intake? I'm not doing that part right. And it's so counterintuitive to me that I'm not hydrating! I want to be able to sing, and have…