brush your teeth

It took me a long time to realize I do this. I'm sure we've all heard it - turn the water off while you brush your teeth. It conserves water, in a place where we have limited water. (I'm not sure how we can be running out of water in the world, while global warming is melting all the ice caps with the water to cover the earth.) The idea is to only use water when you need it. I am sure I could do better - not have so much pressure and such, turn it off a little more. But this is a perfect example of something you should be doing anyways. It took such a long time to notice because I had been doing it. Why would you leave the water on? It doesn't make any sense to me to have it on in the first place. You wet your brush, and you clean it off, maybe rinse your mouth. Why would anybody leave the water on? If you're leaving it on for this, what else are you leaving it on for?