I see it every week - parents shouting and screaming at kids. My dad was the same. He was always there, but he never interfered. Ron Greenwood, who was the manager of West Ham when I was a kid, wouldn't allow any parent to shout from the touchline. He thought players should be allowed to think for themselves.
Down at Bournemouth, I kicked a tray of cups up into air, and one hit Luther Blissett on the head. He flicked it on, and it went all over my suit hanging behind. Another time, at West Ham, I also threw a plate of sandwiches at Don Hutchison. He's sitting there, still arguing with me, with cheese and tomato running down his face.