That's what happened to me yesterday. My daughter and I were reading Roald Dahl's Matilda, in the pitifully edited Puffin edition (see my blog on the BFG here), and when we came to page 37, line 6, Eleonora stopped as she read, "There is is – Fred said – It's name is Chopper", looked at me and said with her big child eyes wide open: "Daddy, shouldn't it be 'its', without an apostrophe?"
She'd just spotted her first typo. At six years and a half. A genius proofreader – a Mozart of the copy-editing world . . . Never was there a prouder editor-father . . .
I speak in jest, of course.