I am reminded of an incident the other day in Tesco.
I'd gone in there with my 2 lads and my neice (grown up neice on husband's side). A woman was there in a scooter. All of a sudden she stops dead. So I stop with my trolley and my children. She starts to move backwards. So I move backwards. At no point has she or the 2 rather charming and oh so lovely women with her, said a word to me. I stand back while she reverses. She then says something to them and they laugh and one says "yes, they'll move "
Last time I checked, I wasn't bloody psychic! If you need to move back, have the bloody courtesy to say "excuse me" or even to thank me for moving back and giving room. But to get in my way, to have me step back to give room and THEN to make a smart arse comment about it, when I'm standing right there? 
I gave them The Look. You know, the one that turns you to dust. 
They were only saved from an eruption of Mount Gob by the fact that I had my children and my neice with me and Himself has banned me from fighting people in the supermarket any more 