I've done it for about as long as I can recall. In kindergarten I was fixated between my thumbs and index fingers, but after everyone started to notice, it's since moved to along my right arm. I wish I didn't, and often I wish my scabs would just go away. Of course picking at them won't help, but it feels like they just haven't been healing on their own either, or maybe not as quickly as I'd like. My mom thinks it's because I'm nervous,, but I don't ever do it actively around anyone else anymore. I don't know. Maybe I get a bit worried at night when I can't sleep and lost in my own thoughts, and I need a sort of distraction. She's joked about me getting a cast, but I really do think that could help. :p