I had a guy insist I use a #000 clipper on his whole head...
So this dude comes in last Friday, says he wants a fade but then points at my clipper guard rack and says "start with the zero, no guard." I asked him three times if he was sure because he had a solid 2 inches of hair on top. He got kinda huffy and said "just do it, man." So I did a #000 all over and he looked like a cue ball. Then he gets real quiet, stares in the mirror for a solid 10 seconds, and goes "oh... I thought you could blend it somehow." Has anyone else had a customer argue with you about a guard size and then get mad at the result?