Forget all those diktats regarding not talking about religion, politics or money. If you really want a quiet life then the question you must avoid at all costs is: "Do you prefer cats or dogs?"
Everyone has an opinion on it and there are those who will defend their opinion with violence. Or at least with a campaign of social media shaming that puts anyone who disagrees with them on a par with serial killers.
You get the picture. Cats versus dogs is an emotional battle that divides people like no other. There's a definite sense that there are cat people and there are dog people and never the twain shall meet.
Statistics for 2017 and 2018 show that nearly half the UK population lives with a pet. A further breakdown shows that most of those people - some 26% - have a dog. Cats come in second at 18%.
We choose our pets for the human qualities we see in their behaviour, hoping perhaps they reflect the way we like to believe others see us. Dog lovers truly appreciate the way their animals are so determined to be part of the team. Dogs are friendly and enthusiastic. They know when you're happy or sad and if you're sad they'll do their best to make you happy again. They're people-pleasers. They seem to understand a joke.
Meanwhile, say dog people, cats are all about themselves. They're aloof. They're disdainful. They'll move in with the couple next door if you buy the wrong sort of cat food. They're loyal to places not people. Larry the Downing Street cat has been there longer than any recent prime minister. Cats are all about being fed gourmet morsels and sleeping on newly washed cashmere. As the quote goes: "Dogs have owners. Cats have slaves."
But that's what cat owners love about them. They like that you have to work for a cat's affection. Dogs are too clingy, too easily impressed. Even Hitler's dogs thought he was great after all. To win the love of a cat, you need to be special.
Cats are sleek and chic, intelligent and not easily fooled. They have undeniable elegance and grace. They always land on their feet. A cat's purr is worth a thousand tail wags. But a dancing dog could be worth 10 million pounds. Take Pudsey, 2012 winner of Britain's Got Talent, who subsequently earned a fortune from performances, books and films.
And dogs will go to war for you, like Bing, the Alsatian collie cross who parachuted with the 13th Battalion, 6th Airborne Division on D-Day. Or Mali, the Belgian Malinois, assigned to the Special Boat Service in Afghanistan, who during an eight-hour assault on a Taliban position in 2012, indicated the locations of enemy fighters, despite being injured by grenade explosions. Both were awarded the Dickin Medal for gallantry, the animal equivalent of the Victoria Cross. Thirty-three dogs have won the medal since the end of the Second World War. More pigeons have been awarded the Dickin Medal than cats (32 to one).
However there have been cat war heroes. In 1854, during the Crimean War, Crimean Tom, sometimes known as Sevastopol Tom, rescued starving British and French troops by leading them to food caches hidden by the Russian soldiers.
That single feline Dickin Medal recipient was called Simon. The black and white cat, who had the rank of able seaman, received his medal posthumously in 1949 for having served on HMS Amethyst when the Royal Navy ship was trapped on the Yangtse River for three months during the Chinese Civil War.
Apparently Simon kept the ship's food stores rat-free despite having been wounded by a shell blast.
And while it may be a long time before we see a cat win Britain's Got Talent and make its owner a cool 10 mil, for some owners, having a cat has already proved to be priceless. Missy, a tabby from Newcastle, detected her owner Angela Tinning's cancer by pawing at her chest, prompting Ms Tinning to get herself checked out.
Ms Tinning told the BBC: "I felt fine and I honestly don't think I would have bothered if she hadn't drawn my attention to it. If it weren't for her, my story could be very different today. She is my little hero."
Likewise, Wendy Humphreys of Wroughton credited her 10-month-old cat Fidge with saving her life. Ms Humphreys saw a doctor after Fidge sat on her right breast every night for two weeks. A scan revealed a malignant tumour.
And in Bakersfield, California, another tabby, called Tara, saved the life of her owners' four-year-old son. When a dog pulled Jeremy Triantafilo from his bicycle, Tara body-slammed it out of the way before circling back to guard the child. The daring rescue was caught on CCTV and became a worldwide sensation.
There's no doubt that each animal has its place both in history and in modern society. The cat's self-sufficiency makes it the perfect pet for someone who works long hours.
Meanwhile dogs encourage us to improve our sedentary lifestyles. Both provide valuable companionship in an unfriendly world.
So what is the correct answer to this thorniest of thorny questions? Cats or dogs? Dare I give you my view?
It's dogs. Obviously. Because while I've lived with and loved both cats and dogs, I have never seen a dog clean its bum on the kitchen table.