I recently had a very minor surgery scheduled to have something removed, on the right side. The doctor was filling out the surgery form and checked the "left" box.
It was because on the form, the "right" checkbox was on the left side, and the "left" checkbox was on the right.
It was because on the form, the "right" checkbox was on the left side, and the "left" checkbox was on the right.
(He immediately caught it and corrected it.)