Shop assistants who seem to have forgotten that the customer is the reason they have a job.

I was in a store a few weeks back, coming out of a side aisle to the main drag when this idiot with a large trolley yells "wait!' and pushes his trolley smack dab across the entrance to the aisle. He then stops it there and proceeds to load a pile of stuff on it. I had to turn around and fight my way through the people down that aisle to get out and down the next aisle. Not so much of a hardship, maybe, but indicative of the attitude of many in the industry these days.