Yeah, some years ago I looked up how a tattoo stays in place, given you shed skin and grow new skin over time...why doesn’t tattoo also go away? Learned that it is because the ink is actually under the skin and trapped there by the immune system reacting to hold it in place. The immune system is fighting and trying to get rid of it and holding it in place to prevent it from spreading into the body.
I'd guess 95%, or maybe more, have NO IDEA of those ramifications.