My 12 year old found my class 7 science notebook at my mother's place and is marking it

We were at my mother's on Sunday and she brought out a box of my old school things. My son found my class 7 science notebook and took it home "for research". He has been going through it with a red pen. So far: two spelling mistakes, one diagram he says is "not labelled properly", and a long comment about my handwriting. He's enjoying himself far too much ❤️