As a Manner of Fact

I was making some breakfast this morning, waiting in front of the toaster and next to the refrigerator which I'm blocking entry access. I sensed someone walk up behind me and stop; they don't say anything, but just stand there, waiting...no "excuse me" or anything. So, providing satisfaction at their attempt of non-verbal communication as to what they want, I stepped aside and they opened the fridge. I was nonplussed at their lack of manners - they are an adult. Ridiculous. Unbelievable. I must say though, that this is not just one occassion they've done this. Several times before they've walked up to my desk and just stood behind my chair and wait until I turn around. Um, aren't you the one disturbing me? Can you atleast say my name or something so that I know you're there, because I may not hear or see you standing there. I don't know why this bothers me so much, but it does. There are few things that irk me to no end and things like this happens to be one of them.