this is a wild one, if you stir an ink drop into glycerine (thick, gooey liquid) between two cylinders, it looks totally mixed. but if you reverse the stirring, it un-mixes back into a drop! no turbulence at that scale so nothing actually gets scrambled, it's all reversible. great party trick for physics nerds.
G.I. Taylor did the original experiments on this kind of laminar flow reversibility, it's a pretty famous demo in fluid dynamics courses.
this is literally used to demonstrate "time-reversal symmetry" in physics classes, it blows people's minds every time.