i have a few that have been active for years. there's one on the edge of my hand between my index and middle fingers' first knuckles that i've had since i was in the army (4 years ago). they die down to scars if i can remember to keep my fingernails short for a few weeks, but invariably, i find myself picking the scar off as if it were a scab and by the time i realize what i'm doing it's too late.
the worst is what i do to my scalp. there are long periods during my work day when i have nothing to do with my hands and i have to talk people through complicated procedures and explain things that they're never going to remember anyways and if i don't have something to distract my hands, i end up ripping up my scalp like it's corn planting season up there or something.
i, for some reason, never trim my damn nails. i need to just put up a post-it by my front door that says "have you clipped your nails this week?" or i'll just keep letting them go.
that might be an idea. a post-it with some kind of doodle that reminds me to not pick at scabs and scars.... meh, it'd work at my desk and at home but it would never work for everywhere else or anywhere in between.
oh well, i guess there are some marks that are just doomed to stay with me forever.