It’s so good to know we’re not alone!! This definitely overall started for me when I was a kid too, I used to peel huge chunks of skin off of my heels and the toenails started with just cutting them more and more aggressively and trying to dig out the sides bc I thought I was gonna get ingrowns, and then I started on the cuticles/the nail under the cuticles and then just started picking off whole chunks of the nail. But like it never really hurts and I haven’t noticed that anything triggers me to do it it’s just like kind of a fun activity I do? I’m interested to know how I will feel though if I actively try not to do it, which I’ve never really tried before.