Back when I was a kid there was an old codger who hauled trash in the neighborhood. He always had a pipe in his mouth. He carried it in the same place all the time and the stem wore a sore on his lower lip. The sore got "really" bad and finally we didn't see him for a while. When he showed up again there was a big chunk of his lower lip missing (looked really pretty). He said he had to have an operation to remove the sore. I think the operation made it easier for him to hold the pipe, as there it was in the same old place.