What's amazing, looking back, is how little the Battle of Clontarf interested us when we were kids growing up on the Northside.
Our parents might tell us, on the smoke-filled top deck of the double-decker number 44A headed for town, that the battle happened near the stream the bus passed, the one whose name they could never remember.
But they seemed bored by it, so we were bored by it, too.
The story was simple enough, perhaps too simple. These horrible Vikings with horned helmets got into boats with millions of oars sticking out each side, left their perfectly good home countries and headed for Ireland to do murder, rape and pillage.
That's what it said in the history book: murder, rape and pillage. The poor harmless Irish lived in constant terror, not least because they were Christian.
Pagans and heathens were naturally aggressive, whereas once you were baptised, you became peaceable and law-abiding from that point on. Such a disappointment, to discover, a little later, this wasn't quite true.
The Vikings had a fair old track record of knocking hell out of us and taking our maidens and our gold, so we built round towers and got a routine going.
The minute someone spotted a boat on the horizon, the alarm was sounded. Anyone who had a gold necklet buried it in the back garden.
If they had a barrel of butter, they would bury it in the nearest bog, where the peat would keep it fresh until after the raid. After that, it was off to the round tower and the last one in pulled up the ladder.
But in 1014, according to the story, the Irish suddenly developed a bit of courage and, led by Brian Boru, turfed the whole lot of the Vikings into the sea in a triumphant one day battle.
But because the Vikings were so horrible, one of their guys, in full retreat, happened on the tent where poor Brian was kneeling to thank God for the victory, and clove his head with an axe before getting away in a boat, the rotten coward. Typical.
That was our understanding of the Battle of Clontarf when we were kids. The great thing about this year's anniversary – and the Battle of Clontarf Festival in St Anne's Park this weekend – is how much it has widened our understanding of the Vikings and of the battle itself.
The Battle of Clontarf was a tremendous bit of warfare, too, not just a disorganised fracas.
It was planned and organised by an old, old man – remember Brian was in his seventies, at a time when people were lucky to live to be thirty. The huge painting generously bought by Kildare Partners and brought back to Ireland after a long exile gives some sense of what it must have been like, as the sun went down.
On the other hand, it seems less likely that the old Us Irish against Those Vikings scenario is true. Much more likely is that the Vikings got entangled in a war Brian Boru was having with another of Ireland's kings.
The unique factor that makes this particular anniversary so special is that it's not, like most anniversaries, a re-run of what we already know.
It's a chance to become engaged with what we never knew, up until the present day.
They may have had dodgy headgear, but the Vikings were a truly heroic lot and we are lucky to carry some of their DNA, never mind how we got it.
They were risk-takers, brilliant boat-builders, astonishing seafarers. They were explorers, city-makers, craftspeople. They probably taught us more than we taught them, and they were pivotal to the creation of what became our capital city.