As a 12-year-old at a family meal, I asked my uncle quizzically why he chose to eat margarine. From another part of the table came the answer: "He doesn't want to die like your father."
My dad had suffered a sudden, fatal heart attack in the late 60s, aged only 52. That kitchen-table comment gave me something to blame. From then on, I was utterly convinced that butter equalled death.
From the 70s onwards, this was a popular belief. That yellow block of dairy was the dietary equivalent of a grenade with the pin out. We imagined the cloying fat it contained would seep into our veins until it stopped your heart like a clogged drain.
But now butter is back in favour, and margarine is out of favour instead.
Last week, the food-giant Unilever announced corporate changes that have led industry-watchers to speculate it is pulling out of producing margarine due to plummeting sales.
Unilever's success is founded partly on margarine, which for decades was hailed as the heart-friendly alternative to butter.
The company was born in 1929 through the merger of British soapmaker Lever Brothers and the Dutch firm Margarine Unie, which began making the plant-derived spread in 1872.
Today, the company is the world's largest margarine-maker, with brands such as Flora and the doughty Stork, which was launched in 1920.
Before World War II, Stork was advertised as The Energy Giver to dispel thoughts that margarine was unhealthy. Originally made from beef fat and milk, most margarines are now made from a variety of vegetable oils, such as sunflower.
But now the knives are out for marge. In a financial report last week, Unilever admitted that it was not "able to stem the sustained market contraction in developed countries".
The major problem for all margarine-makers is the dramatic rehabilitation of butter's reputation.
In the past few years, a turnaround in expert health advice on dairy fats has transformed butter from fridge-shelf pariah to the golden boy of healthy spreads.
We increasingly understand how the whole anti-butter argument sits on shockingly shaky foundations.
This bad butter fallacy goes back to 1913, when a Russian researcher, Nikolaj Nikolajewitsch Anitschkow, fed large amounts of animal fats to rabbits and showed that their cholesterol levels rose dangerously.
He ignored the fact that rabbits do not naturally eat dairy. Their digestive systems can't cope. Humans, meanwhile, are perfectly capable of digesting dairy.
Nevertheless, other scientists ran with the idea.
In 1953, Ancel Keys, an American physiologist, examined data from six different countries and claimed to have discovered a firm link between saturated fat intake and coronary heart disease.
Keys' research ignored clinical reports from European countries such as Spain and France, where the traditional diets are heavy in fats, but the rate of heart disease is low. He claimed that he could not find good data to include from these countries.
His study prompted a widespread fear of animal fats.
In 1957, the American Heart Association began to target fat consumption as an enemy of cardiac health. Fat avoidance became US policy in 1977. Now, scientists are exposing the hollowness of this dietary diktat.
For example, a study in the British Medical Journal three years ago showed that middle-aged Australian men who had followed health advice and eaten margarine instead of butter actually had higher death rates.
One explanation for this is that the oils in their margarines were high in omega-6 fatty acids. These actually displace heart-healthy omega-3 fats from the body.
Moreover, high levels of omega-6 fats in the body can cause inflammation, which may, in turn, cause cardiovascular disease.
And last year, a major review of research evidence in the BMJ journal Open Heart overturned 30 years of health advice telling us to avoid butter and full-fat milk.
The official advice - that we should cut our intake of saturated fats, such as butter, to only 10 per cent of our daily diet - "should not have been introduced", experts said.
Such revelations have prompted a renaissance for butter.
The bad news for margarine
While butter is receiving well-earned pats, the health news for margarine just keeps getting gloomier.
Last year, for example, investigators warned how chemicals called emulsifiers - which are used to make margarine smooth - can disrupt the vital healthy balance of bacteria living in our guts.
This can inflame the intestine, which raises our risk of developing inflammatory bowel disease, according to a study in the journal Nature.
Worse still, Georgia State University researchers have found the inflammatory disruption can also lead to people piling on dangerous levels of weight, raising their risk of heart disease and diabetes - the very illnesses we have spent decades trying to avoid by ditching butter for marge.