Waxing and waning

I give Emma her insulin injections morning and evening, and noted tonight that after I give her the injection, l rub the area where I've given it. Why? I think it might have to do with waxing - and the story Charles told one day after the Footy Show. It was the first Footy Show I'd seen and in a charity challenge, some guys would receive a couple of hundred dollars for having bits of hair on their body ripped (oops, I meant waxed) off: bikini line, chest, eye brow - that kind of thing. They did it, but they had tears in their eyes and it looked like a very painful experience - confirming stories I'd previously heard from women who endure it regularly, only because "you get used to it" or "it doesn't seem to hurt as much".
When water-cooler conversation turned to it the next day, Charles - a regular participant in the Gay & Mardi Gras Parade - said when he had his lower back waxed, he didn't feel pain. You only feel pain, he explained, because your skin doesn't know how to react. His waxer rips off the strip with one hand and gives the newly-denuded area a good hard slap with the other. This, Charles assured us, means the skins knows that it's been hit - rather than all the nerve endings running around screaming "what's happened, what's happened". That's the theory anyway, and I'm going to have to take Charles' word for it because I'm not going there! No point trying to a an empirical test if that one can't actually "remember" the intensity of physical pain. Or Sooz suggested it might be the "a new pain overrides an old pain".