I was astonished by ingenuity of many users who demonstrated reasons for why rotational matrices are not commutative.
However in 3d rotations I'm more puzzled by some other theorem ...
How intuitively to show that
composition of rotations about fixed axes of global frame is equal to composition of the same rotations about their current X,Y,Z axes but made in reverse order.
In the previous question the most interesting to me was example with permutations... Maybe someone also knows such nice examples..