you would not believe how common it is. It's like making a class of highschoolers take a colorblindness test. There's always ONE who had no idea
sidenote, it's really sad how the education system won't even spend 10 minutes a year to diagnose something that effects millions of children. There's FREE websites that they can just open on their board or projector
I remember on Reddit I'd see like a post a month from some uneducated pirate person asking how to fix a utorrent issue. It was fun watching them try to justify using it with all the other legit, updated clients. It didn't ever go well for the OP.