It's also the idiots who insist on riding side by side on a bike path taking up the full width of the path going into a blind corner. Or the idiot who rides on the wrong side into the same corner.
As an old roadie who as a teenager, grew up riding in pace lines with my friends, I'm amazed at what people (all adults) will do when they are on the road or worse on a bike path.
I tell them, stay on the right in single file , if you're going to stop, get off the road/path and try to ride in a straight line. Most of them aren't even wearing a brain bucket but I usually leave that little fact out because it seems to be too much information for them to digest at one time.