It is Saturday 30th April 2016. Around midday, I was in the checkout aisle of Sainsbury’s Colchester Avenue superstore. I have been a regular there for twenty-three years and know many of the staff well-enough to pass the time of day with. Before today, I had given little thought to the fact that shop staff must also necessarily recognise customers and their (our) little habits. Then one of the members of staff made me cry. I know what y’all are…