Reading this thread is fascinating. 
I scratch my cuticles with anything sharp I can fashion: Foil wrappers, bed sheets, exact-o blades. I avoid using anything like an exact-o blade, because with something so unyielding I'll scratch them till they bleed.
It's obviously a self-soothing behavior, but other than that, I have no idea why I do it. I've done this since I was a tiny child.

I scratch my cuticles with anything sharp I can fashion: Foil wrappers, bed sheets, exact-o blades. I avoid using anything like an exact-o blade, because with something so unyielding I'll scratch them till they bleed.
It's obviously a self-soothing behavior, but other than that, I have no idea why I do it. I've done this since I was a tiny child.