My university had a cruel architecture program. They would admit a mess of kids and then flunk 70% of the in the first semester. The process involved lots of amazingly hard design problems; like “Create a small unmarked uniform box which the instructor will place on table right side up on his first attempt, no text is allowed. Due tomorrow.” Did I mention the art supply store was closed?
Watching people work on these made me much more aware of design, and its curious perversities, and that some instructors are sadists.
I was reminded of that today glancing at my screen with my glasses off. There was a wonderfully ambiguous icon on the screen. It was either a triangle pointing to the left; or it was a volume control showing a speaker facing to the right. I’d not noticed this before. A cone is ambiguous about which way it is facing.