I feel really rebellious when I don't turn off the water when I'm brushing my teeth
Does this make you feel like you are doing something dangerous?
Why do people bother to turn the water off when they brush?  It's not like they're saving enough water to do anything useful.
It doesn't sound like much, but if everyone takes small steps to save a little bit of water everyday, it really does add up to a significant amount.  And, besides, doing something wrong just to rebel doesn't solve anything for you, and it doesn't make your life any better.
That's messed up, everyone turn the water off when they brush. Screw preventing ourselves from saving water.
Don't you worry for your future as well? If there's no water then everyone's not going to have a good time. How about reading up on how it really does save the environment, instead of going against society?