Doesn't help if the doctor's question was "Am I cutting into the right side?"
“It’s my right, your left” (not common but has occurred multiple times).
The more frequent one is where someone is trying to say “medial side of left leg” and say “it’s the right side of of my left leg”.
It seems dumb but if it saves me from having someone dissect my right knee when I wanted someone to bolt a new AC ligament into my left one, I'm all for it.