I guess the point is, particularly with football, you really have to pay attention to the players when talking on the sidelines or looking through a 200mm or 400mm lens, either of which tend to give you a very narrow view of the world. Add all the folks just hanging out on the sidelines and things can get interesting fast.
So if you find yourself shooting from the sidelines or just hanging out and you aren't one of the guys in helmet and pads, you might find this message thread eye-opening.
Stay safe...