This is a very apt thread. I continuously run into folk here in Texas who have no idea there are any number of "un-posted" places that are forbidden (because they always have been that way). Hospitals, Post Offices, Amusement parks (of certain dimensions); horse tracks, all manner of places.
It 's the same here in Missouri too. Not everyone knows where they can or cannot carry especially after permits carry went into effect. At least with the need for a permit everyone had to take a mandatory class that went over all the places you can or can not carry,