My girlfriend did that… Woke up in the middle of her shoulder surgery, as the doc was grinding bone away. She asked them to turn the monitor so she could watch. Doc did a double take, moved the monitor, and let her watch for a little bit… While motioning to the anesthesiologist. They must’ve bumped up the meds and knocked her out again, because she went back under.
Some of us have solved the problem by performing a “clean Linux install” instead.