Three things I think about almost every time I shower:
Eddie Izzard - one nanomillimeter between fantastically hot and fucking freezing
The Bernoulli Effect - my high school physics professor didn't say much that stayed with me. But one thing stuck like shower curtain to a wet leg.
The Newlywed Game - ok not this clip but it made me laugh pretty hard. One show asked the guys how they would describe their wife's shower habits. Top to bottom/bottom to top, left to right/right to left, or front to back/back to front. I think about it almost every morning wondering how a partner might describe mine.