(Content note for implied gore)
The other day, I was reading some autism blog or other, and saw mention of people taking potato peelers to their arms.
I am an adult who knows better. I did not go and find a potato peeler and run it up and down my arm.
But I did consider it, briefly, before thinking "I am an adult who knows better". Possibly just to see what it felt like. This is probably a sign of a mental instability of some sort.