Thanks for all your responses; glad it's not just me. (Would have replied sooner but I'm a pauper with no web access at home). fili_fole, in our local shopping centre you always get people who think that the top of a moving escalator is a good place to stop and yak as well. I give them a suitably grumpy stare and mutter something damning, but then they just assume I'm the local bag lady or something.
And SixKitten, did you see that documentary last year about a bloke who was freaked out by tinned beans, he was undergoing desensitization therapy for it? Don't think it worked in the end.