Wow! Sorry to hear about your experiences, and you are right, nerves are there for a reason. I remember reading about some surgery that Joni Erickson-Tada had done after she became a quadriplegic. The goal was to shave down her hip bones to prevent bed sores. The surgeon didn't even bother to anesthetize her, knowing she'd never feel it (not much different than having an epidural and being awake the whole time). After the surgery, she sat up as she was taught (she had feeling from the shoulders up), and the doctor ordered her back down. Sitting up like that ripped out a number of sutures.It's possible the knife hit nerves that otherwise would have caused intense pain. I had a Lipoma tumor in my back once. I didn't know it was there until one day I noticed that every time I moved a certain way, I'd feel a sensation in my back that would cause me to suddenly giggle or laugh. It was like I was being tickled. Anyway, it was discovered that I had this benign tumor. I had it removed in the outpatient facility at the hospital. I had a localized anesthetic, although the doctor began cutting almost immediately before it took effect. It never really hurt, even afterward or days later. Oddly, I could feel the blood oozing out from the wound when the doctor was cutting. It felt like ice water. Also, I could see most everything the doc was doing. I was facing a cabinet with glass so I saw it all. The stitches didn't hurt - even after the supposed anesthetic wore off. The real horror was after a few days, I was shopping and the wound somehow came open. I remember some lady screaming and running up to me. She thought I had been stabbed or something, because there was blood all over my back. I never felt any sensation or pain as one would feel if their back had been entirely wet with blood from an opened wound. I went to the ER and my doctor came in to see me and told me I probably should have been kept in the hospital because the surgery was pretty deep. Nice. Did he once think that I could have possibly bled to death!? Anyway, the point is, when nerves are cut, a person may not be aware of an injury. That's why we are meant to feel pain when something goes wrong, otherwise we wouldn't know it and would bleed to death or be unaware that something was wrong.
I believe I have lipomatosis as I've been covered with what feel like lipomas my entire adult life. However, I had something on my back I thought was a lipoma. But one day, I was feeling it and realized it had no pain and was firmer than the other lesions, and I thought it had gotten larger. I got to kneading it, and something hard started coming out like a plug. Then as I continued to squeeze, a long fatty "string" kept coming out - enough to make about a 4 mm ball. So it was not a lipoma, but an impacted sebaceous gland. I still haven't figured out how it got that impacted without getting infected and forming a boil. I guess that saponized "plug" formed a very good seal.
Sorry if this is TMI.