I had poison ivy on my ankles, that I was REALLY good about not scratching. So one night, I slide off the couch to play with my Dachshund on the floor, and in doing so, rubbed an itchy spot on the carpet. Now, my carpet is one step above prison-grade industrial, so it's pretty scratchy. Well, when that itchy spot met the scratchy carpet, it felt good. It felt reeeeaaaallll good. So, I rubbed it on the carpet a little more. Then some more. Then it went into a whole "friction-burn-inducing" ankle rubbing frenzy. Resulting in a half-dollar size abrasion. which scabbed over, and you know the rest of the story.