Or for doing a thing that seems smart on your level, such as publicly correcting your teacher's mistake. Yeah, it's obvious to us why this is probably a bad idea, but not to a 10-years old child.

I just got a new appreciation for my country's school system from the fact that this probably being a bad idea wouldn't even have occurred to me without you mentioning it. When I was 10 - or for that matter any age - and disagreed with my teachers, they'd just look up the right answer in some authoritative reference and admit to being wrong if necessary. I thought this was the norm everywhere.