I live across the street from a farm. God only knows what's grown there. It's not corn, and it's not tobacco, which are our two primary crops around here.
Connecticut isn't known for its farmland. I was the only one who looked at the tractor sign and went "I know what that is! We have those signs in my town!"
Because that's all the stuff you learn just by riding around with your parents. I thought it was funny, in my classes, when I was the only one in the class who knew what a tractor crossing sign looked like.
I would think headlights are self-explainatory. Night, rain, snow, things like that. Most of my driver's ed classes included movies. there was only eight hours of instructed driving. the other twelve hours were outside of class.