I went to tell Celeste good night tonight and ended up knocking over a bit of her furniture. Rewind (that's probably the best idea). After running tonight (and spending some time sitting around in the backyard cooling down), I went upstairs to tell the girls good night. While talking with Celeste, she mentioned that earlier in the week, she'd been spinning around in her room and it made the ceiling fan slow down.
Never being one to pass up the opportunity to explain a physics concept that I'm probably not 100% on top of, I decided it was a good opportunity to explain Einstein's theory of special relativity and how, if one rotates under a ceiling fan in the same direction as the fan then the blades will appear to slow down or, if the speed of rotation at the point of observation matches the speed or rotation, stand still.
To be completely fair, I didn't use the phrase "special relativity" or even "relativity" in the conversation and I may be misremembering or misunderstanding the concept. However, that's all moot because of what happened.
As I tried to explain to Celeste how movement of the observer could influence the perceived motion of the fan, spinning around in a circle, I got progressively dizzier and dozier until I found myself falling over and crashing into her dresser and toy chest.