The three biggest things that get my goat are the guys or gals who ask you for help and then completely ignore any advice you offer. You can tell them, but you can't make them listen. Part of it is I'm a pizz poor teacher.

The second is the guy or gals that think quantity trumps quality. They have this thing in their heads that says if you fire enough ammo magic is going to happen. They ignore the basics and just shoot, usually all over the place forever.

The third are those that are stuck on speed and think getting as many rounds down range as quickly as possible is going to increase their chances of hitting the bullseye.

I've about given up on teaching anybody. I'll take them to the rage and show them, but won't try to tell them. IMO TV and video games have ruined any chance for most young people to learn accuracy, their preconceptions make them almost impossible to train.