Anecdotally: I had surgery under general a couple of years ago no side effects. I’m 60. Anesthesia is poorly understood. How can a noble gas be anesthetic?

Anecdotally: I had surgery under general a couple of years ago no side effects. I’m 60. Anesthesia is poorly understood. How can a noble gas be anesthetic? We understand it so poorly that both your experience and mine could be common