Some phenomena in physics defy intuition. Others have very intuitive explanations which you could explain easily to a layman. Sometimes, these intuitive explanations are simply wrong.
What phenomena in physics have intuitive, but totally wrong, explanations? An explanation you could use to easily convince your non-physicist spouse: something that would make them think they understand what's happening while being incorrect?
I'll present one (somewhat contrived) example:
Bernoulli's principle is often used to explain how airplanes fly. After explaining Bernoulli's principle, the layman might ask "okay, so why does the air on top of the wing move faster than the air below it?" A seemingly intuitive explanation is that because the wing is curved, the top surface has a longer length from leading edge to trailing edge than the bottom surface. Therefore, if two air particles hit the leading edge simultaneously, and one travels above the wing while the other travels below it, the one traveling above must move faster in order to arrive at the trailing edge at the same time as its under-wing counterpart. This explanation is totally wrong because there is no rule of physics that states the two particles have to arrive at the same time. (And a non-curved "barn door" wing is quite capable of producing lift.) So the phenomenon here is genuine -- a wing does generate lift, Bernoulli's principle is involved, and the air above the wing is moving faster and has lower pressure than the air below it. But the "two particles racing each other, ending in a tie" explanation is simply wrong.
