A few years ago, before smoking was outlawed in pubs,
my friend and I wandered into the Green Man to find a man remonstrating with the barmaid. The pub had put up a small sign asking patrons not to smoke at the bar, with which this particular patron had obviously taken issue. There were plenty of other places in the pub that he could have gone with his cigarette, but no, he wanted to smoke it at the bar. Trying her best not to lose her rag with this objectionable specimen, she eventually just told him (politely) to finish his drink and leave while she tried to serve us.

Not content with this outcome, the surly customer turned to us,
"Do you smoke?" he asked,
"No," my friend replied, "but I do work in a pub, and it's not particularly nice having customers blow smoke in your face; I can see why they put the sign up."
"But you don't smoke yourself?"
"No."
"Oh, so it's like talking to a mackerel in a pond?"

We were slightly taken aback by this somewhat non-linear approach to argument, to say the least. This was, however, not the strangest thing this man said to us.

After a moments' confused pause, my friend thought he'd outwitted this chap when he came back with,
"You won't find mackerel in ponds. They're saltwater fish."
And then, deciding that his unique style of counter-argument would be more useful at this juncture, this chap just ruffled his feathers and said,
"Yeah, well it's like saying 'mackerel eat strawberries,' isn't it? That's what that sign says to me: 'mackerel eat strawberries.'"

We told him he was just being silly now, and found a table at the other end of the pub.
(LongJohnBaldry, Mon 12 Sep 2011, 15:15, Reply)