@ttscoff I found out that I have a natural immunity to lidocaine while in the Army. I was driving an armored personnel carrier that slid down a wadi (dry river bed) and when it hit the bottom my chin slammed into the driver's cupola, splitting it open. The medics shot lidocaine into my chin until it looked like I had a balloon growing out of my face but I still felt every stitch as they sewed me up. Side note: Also had my wisdom teeth removed by an Army dentist while out in the field that same year.