For reasons explained the other day, I obviously didn't watch any of the longest tennis match ever played at Wimbledon.
But I couldn't help noticing on the news that John Isner was wearing a backwards-pointing baseball cap.
It reminded me of a friend who, on on a ski holiday in the USA, became so irritated by the sight of skiers wearing baseball caps back-to-front that he went into a sports equipment shop and asked if he could buy a backwards-pointing cap.
He claims that his request was taken seriously by the shop assistant, who explained that they didn't have any and helpfully suggested another shop in the same street that might have some in stock.
But it is, I suppose, just possible that the shop assistant was joking too.