I used to work in restaurants when going to university, and I gained a pain tolerance to hot things. I no longer felt pain when handling VERY hot plates and water. Now, many years later, that pain tolerance is entirely gone. To the point that the same things I could hold forever back then with no pain now hurt so bad my body forces me to drop them.
How does this work, how does the body ‘learn’ to change the threshold before pain is felt, and why does it eventually revert back to normal?