I live near a river that flows backwards for some 50km or so with tides. The first time I saw it, I thought I'd gotten turned around because surely water can't flow uphill, right? It's fun to find out that one is so wrong about basic physics.

Reminds me of the time that Bill O'Reilly argued on national television that tides were inexplicable.

https://www.youtube.com/watch?v=NUeybwTMeWo