https://www.mercurynews.com/2022/05/12/ask-amy-i-dont-know-how-to-explain-my-scars-to-children/

Dear Amy: When I was a teenager, I self-harmed and as a result have visible marks on one of my arms. These are left over from that time when I deliberately cut myself.

I often forget that these scars are there, and most people don’t say anything about them, except for children.