Schrödinger's Test
When someone says something completely out of left field to a stranger, and based on their reaction, decides if it was a test or not.
Schrödinger's Test Guy: *insert offensive or ridiculous thing*
Guy: "What the fuck???"
Schrödinger's Test Guy: That was a test, and you just failed.
Guy: "What the fuck???"
Schrödinger's Test Guy: That was a test, and you just failed.