Umer Ashraf is an entrepreneur who owns the Glasgow-based iCafé shop chain, as well as smoothie and juice bar Paradise Bay, in Oban, Scotland

Quotes are beautiful things. They colour the canvas of conversation and often express the most complex elements of the human condition clearly and concisely. I usually quote the likes of Shakespeare, Socrates and Martin Luther King when I am discussing current affairs with friends. But recently, I found myself (in what one could justifiably call a rage) quoting Ghandi to a frightened pseudo-checkout operator while buying milk from Sainsbury’s.

Let me elaborate. I have high standards when it comes to customer service. I like connecting with human beings and find great joy in brief social encounters. So I’m a great believer in the virtue of patience and normally have no problem queuing at checkouts, as often the wait is well worth it. For example, earlier in the day, I was in line at WH Smith to pay for my FT Weekend. On reaching the counter, before me was the face of a beautiful young African woman with the world’s biggest frown on her face. Her beauty was a relief given that, a quick flick through the FT while waiting meant all I’d seen for the previous five minutes were pictures of Angela Merkel, William Hague and Vince Cable! Yet her frown disheartened me. I could see she was frustrated at having to serve misanthropes all morning who neither said please nor thank you. So I made it my mission not to leave until I had cheered her up. It didn’t take long. As she handed over my receipt, I asked her to bin it for me. Pointing to the FT I said: "Unless it is really bad news, I won’t want my money back". She lit up with a large smile. Mission accomplished. We had transformed what could have been a mere commercial transaction into a social one.

Popping into Sainsbury’s on the way home, all I wanted was a bottle of milk, but as I went to pay, all the checkouts were closed during a peak period and all I could see was a swarm of frustrated customers dashing to and from malfunctioning self-service checkouts. Never before had I used one of these machines, but I was not given a choice, and everything that could have gone wrong did. It wouldn’t recognise the bar code, it wouldn’t accept my coins, it kept vomiting vile dictatorial commands, such as "remove item from this area". I was delaying the long queue behind me, full of growling customers.

With my patience tested to the limit, I let rip on the customer assistant. "Why do you have these bloody things"? I yelled! The entire supermarket froze in silence except for that dastardly machine. The trembling assistant replied: "I’m sorry sir, management make all these decisions; they think it will speed up customer service."

Instantly, I thought of Ghandi and quoted: "There is more to life than increasing its speed," before walking out.

Back at home, with no milk to enjoy a hot chocolate, I opened the FT and read this headline: "UK supermarkets to increase self-service checkouts".

"I want my money back," I yelled out, only to remember what I’d said to the assistant at WH Smith and, in tandem, the most common platitude of all: "Be careful what you say."