I used to bite my nails down to the nub to the point where I'd tear out the membrane and hurt myself something fierce. Then, when I was 16, I saw the movie Angel Heart and couldn't tell if Robert DeNiros' nails were real or fake (he IS a method actor), but decided to give it a try anyway because his hands moved so elegantly with them and he WAS intimidating.
It was very hard not to bite them, but I let them grow and grow and even took up filing them to keep them looking like DeNiro's. After about 6 weeks, they were a beautiful Luciferian design and pristine clean. But typing was hard and I constantly had to file them because they were so soft that little nicks came easily (I wash my hands up to 15 times a day). It was interesting to see the reactions of people who saw this tall, clean-cut, well-dressed teenager nevertheless donning these Satanic nails. I wanted them to grow even longer, but 2 things changed my mind:
1. A group of fucking 11-12 year old kids came up to the register where I worked and huddled up after they saw them. The others bolted out of the store and the remaining one said to me: "Uh, my friends wanna know...are you a switch hitter?" and took the fuck off before I could chase after him. I did NOT need to take that from little tweener shits.
2. Because I'd bitten my nails so much, my parents never checked on them. But, lo and behold, my mother spotted them and told my dad, and my dad in a fit of incredulous frustration asked why in the hell I didn't cut my nails? Was I trying on purpose to look queer? People'll think you're gay!
So not wanting to put up with either of that shit for any longer, I cut them. And my fingers hurt like a motherfucker for 3 days afterwards.
But something good came out of it: I haven't bit my nails since.