Lyn, it sounds quite Hitchcockian. I used to spend my summers by the sea near to a port and I remember the herring gulls as handsome, noisy chancers. I don't remember being scared of them.
My theory is that in the fifties and sixties there were no fast food restaurants. People ate breakfast, lunch and dinner (or in my case, breakfast, dinner and tea) at home. It was considered to be very bad manners to wander about in the street eating anything other than maybe a boiled sweet. I remember getting detention at scondary school for being caught serruptitiously munching a bag of crisps on the bus home (one of the teachers lived in the same village and reported me, the b*****d).
Also, there just wasn't spare food to throw around (literally) so people rarely fed the birds and the birds didn't expect to be fed. Nowadays everybody eats all day long and throws waste food wherever the fancy takes them. Birds are quick learners and the gulls have learned not to bother waiting for scraps to be thrown to them but to go in and grab what they want.
We only have ourselves to blame.