In training right now as a new football ref. Watching the game, covering the game as a journalist, coaching the game at the youth level and being around it for 30+ years I thought I knew most of the rules but wow, looking at the materials and what's expected I've found a whole new appreciation for this even ahead of my first game.
Depending on role (Back/Side Judge/Linesman, etc.) you have to know your keys, responsibilities, where to lineup, what to watch and that's even before there's a penalty, etc. At least in high school football you have a crew, you are fairly far removed from the fans vs. basketball, etc.
Long ago I concluded that before anyone could coach at any level, they should have to officiate their sport for a significant period. I also believe coaches would do themselves and their players a favor if they held intrasquad games and required their players to officiate. I've had my run-ins with officials, but I do believe having some experience on that side of things would provide some perspective and understanding--even empathy--that nothing else can. And perhaps that would be good for everyone.