A long, long time ago I was in a fish and chip shop in Edinburgh, very close both to the tennis club where I’d just played a couple of sets and to my home. In fact it was a handy stopping off point from one place to the other, solving dinner at the same time.

I was with another English chap that I didn’t know very well. He was in banking, very ambitious and very clear on his career and financial goals. We weren’t very alike but we shared an interest in tennis, that was about it. There were half a dozen people in the queue.

I noticed a scruffy looking small dog come into the chippie and start sniffing around. I said to my tennis pal, in quite a low voice, jokingly, something along the lines of ‘is that a dog in the place where I’ve chosen to get my dinner?’

This drew the attention of an equally scruffy looking man in the line, the owner of the dog as it turned out, who said, not jokingly, something along the lines of ‘of course it’s a dog you [insert anglo saxon epithet of choice here, in a broad local accent]’, which also carried the clear threat of ‘what are you going do about it?’

I instantly raised my eyebrows, as many of us do as a stalling mechanism as we consider the multiple different ways this conversation should progress. My tennis pal shook his head. We moved on, got our food, and left.

What he said afterwards has stuck with me ever since. ‘That was a no win situation. You can’t go there. You’ve so much more to lose than him.’

This is true not just in life but in business too. If you risk being drawn into any competitive situation with a bottom-feeder, be very careful before you decide to engage.