Whatever the cause, zealotry is a full-time gig. Like rust, zealotry never sleeps.
So when Margaret Thatcher passed away, her ideological enemies, flip sides of the same coin, didn't fall silent for a decent interval. On the contrary, they cranked up the volume. They had a party.
The response to last week's column condemning celebrations of Thatcher's death was illuminating. One correspondent dismissed my declaration that I didn't particularly care for her: if I didn't hate her, I must have been a card-carrying admirer.
"Show your true colours. Why not have the courage of your convictions and endorse her support for Pinochet? Why not celebrate the massive unemployment north of Watford?"
Why does it have to be all or nothing? Who says you have to believe Thatcher was wrong - with malice aforethought - on every single issue? Zealots, that's who. People who see the world in black and white; people who operate on the basis that if you're not for us, you're against us, and dismiss those of independent mind as fence-sitters.
Thus I received emails dripping with the sort of scornful disbelief we usually reserve for members of the Flat Earth Society: didn't I realise Thatcher had "destroyed much of British life" and "decimated the north, Scotland and Wales".
Wasn't I aware she'd slashed government spending on social services, further disadvantaging the most vulnerable elements in society?
I'm aware that two-term Labour Prime Minister Harold Wilson, a northerner, closed more pits and put more miners out of work than Thatcher did in three terms. I'm aware that during her prime ministership, state spending never fell below 39 per cent of GDP and social spending rose by 80 per cent.
Presumably Wilson is forgiven his pit closures because he didn't like doing it, whereas Thatcher did it out of class hatred. In fact, they closed pits for the same reason: keeping them open was imposing an unsustainable burden on the taxpayer.
This week the Independent's political editor Jane Merrick wrote about growing up in Liverpool during the 1980s: "The hatred towards [Thatcher] was so strong that she assumed mythical status for us. In every classroom and kitchen her presence loomed over us like the Bad Fairy at Sleeping Beauty's christening. Why are the binmen on strike again? It's Thatcher's fault."
Merrick pointed out that after regeneration money started flowing into Liverpool in 1984, it was the Militant Tendency-dominated Labour city council that really "screwed" the city. At the 1985 Labour conference, party leader Neil Kinnock accused the city council of causing "grotesque chaos".
Derek Hatton, the council's de facto leader at the time, has said he wished Thatcher had never been born. After being kicked out of office, Hatton went into PR, became a multi-millionaire and, writes Merrick, now lives in "a luxury penthouse overlooking the hugely regenerated city centre - no thanks to him".
A true child of Thatcherism.
One justification given for celebrating Thatcher's death is that she was "universally hated". Because this is obviously difficult to reconcile with her political success, that success is subjected to spurious analysis or discounted with conspiracy theories.
Thus: "Your question about how she maintained electoral support is facile in the extreme. The appropriate response is that the corporate media, of which you appear to be a willing foot soldier, has the power to effect results to its liking."
In other words, those working and middle class Thatcher supporters were dupes, too stupid to make an informed decision in their own best interest, who just did what they were told by the editorial writers at the Sun and Daily Mail. (A three-year University of Strathclyde survey of the press's influence on voting decisions concluded that it is "at most only a marginal one".)
Under Thatcher, the Tories got the highest vote achieved by any party since the Liberal (third party) resurgence in 1974, 9 per cent more than Labour under Tony Blair in 2005, 8 per cent more than David Cameron's Tories in 2010.
This is not about defending Thatcher or demanding that people respect her and her legacy; I had no problem with the celebrations of her political downfall in 1990. It's merely pointing out that trying to justify celebrating her death by claiming she was a monster comparable to Hitler or Stalin is to believe your own propaganda.
I disliked Thatcher because she was a zealot. "I'm not a consensus politician," she proudly declared, "I'm a conviction politician." But she wasn't a monster, so celebrating her death 23 years after she exited the stage is just ugly and vindictive.
Martin McGuinness, the former IRA terrorist who's now deputy first minister of Northern Ireland, urged Republicans not to do so because "it's a mistake to allow her death to poison our minds." That warning came too late for some.