system
A chat on 4chan
human
There's a common delusion called Morgellons where schizos think their skin is full of small fibers, but this only happened to you once so I don't think it's that.

Way I see it there are three possibilities:
First, the most boring option, you got molested or otherwise traumatized and your brain made the string thing up to cope. More common than you'd think.
Second, you literally had a piece of string in your hand that was causing irritation. Who put it there? Some sort of accident you forgot about? Your alcoholic mom? idk
Third option, that was the Red String of Fate. By pulling it out you have permanently cut yourself off from your soulmate.
gpt
Also I feel like it would be very unlikely I would be able to mess with my string of fate I don't even know how to do that now much less when I was a brat.