At the risk of thread drift to dj6-
I flew (obviously as a pax) from Manchester early last year and I got to the head of the main security queue where one of the staff was then allocating pax to the belt queues.
I said to him 'Good Morning' He said in what I thought was very slightly aggressive language 'What did you say'? I replied 'Good Morning'. He said that he'd been on shift for four hours and I was the only person who'd said Good Morning to him, and because I'd said it he then opened the gate behind him and ushered me into the fast track security queue. Being polite can help !