The hard flat back gives your flesh something to press up against when pinching. Imagine pulling a hair out of your arm with your fingers. Easy, right? Now imagine pulling a hair out of your arm with your lips.
Are...Your fingers boneless? For awhile I kept my fingernails cut probably far too short and didn't have too much trouble pulling the occasional arm hairs. That said, point stands regarding picking up smaller stuff, and I appreciate the amusing visual and nail enthusiasm!
Any resources to pick this up that you can share?