Encounters with Security Guards and their Secrets

The Sainsburys down North Street at lunchtime. I was buying a Yorkie bar and a £1:00 sandwich from the self service tills. There was a long queue toward the normal tills. I don't know why no-one used the three or so self service tills. After paying, I, for once, remembered my receipt. An older security guard came up to me. 'Can I see your receipt?' he asked me in a voice that immediately made me realise that he had failed to become a policeman. He looked at my receipt - grunted - gave me back my receipt and walked away.
I wonder what I had done that made him suspicious?

I had a late call that took me until about 7:10pm. Everyone else had left the call centre. I was aware of a sudden silence descending, and also that there are noises in that silence. I pass the photocopier and it seems to breathe. The buzzing of the fluorescent lights is loud as summer night insects. I step out of the call centre and press the button for the lift, and realise that I am confronted with that presence that must always come when a building empties. The lift takes a long time to arrive. I remember; the coolness of the air, the door closed to the call centre proper - I could see my desk silent and guilty - an empty mug, my file, the folded up poster of Esben and the Witch that I haven't taken home since I bought the album back in February.
I breathe that hushed intimation of other spaces, other corridors, other levels. I kiss those
stairways opening up in new annexes.
This is the secret geography known by all security guards, all night-watchmnen.
I stepped into the lift, eager to be heading home.
I was in a new country without a map and feared becoming lost.