Say you are from France, or Central Asia, or the Mississippi Delta. You have never been to Northern Ireland before, but you are with a group of students, or artists, on a visit and the Northern Ireland Office, or the Arts Council, or your professor, has arranged a crash course for you.
Wisely, or otherwise, I have been picked to explain the history of the conflict to you. It happens. This is what you get.
Go two miles in any direction from Belfast city centre. Walk down any street and every person you pass on the that street, pushing a pram, or smoking outside the pub, will be from the same community as every other.
They will all be – and I use these false labels for convenience – either Catholic or Protestant. They might not describe themselves by one of those words, or even as nationalist, or unionist, but they will be identifiable as part of what we all know as the nationalist, or unionist, community.
That doesn't mean they will all be sectarian, far from it; but they will know who they are and that they are not the other.
The key fact about Northern Ireland is the separation of communities. This separation goes back 400 years and it is not getting better; it is getting worse.
There are no physical attributes defining membership of these communities, though there have been rumours that some dig with a left foot, pronounce Aitch as Haitch, or have eyes that are closer together.
We have ethnic division without the handy marker of skin pigment that helps you tell who's who in, say South Africa, or New York. As a result, we have city centres in which both move freely and genially among each other. Some people will have told you that the conflict is about religion. But many of these people have little, or no, religious sentiment, or routine in their lives.
It wasn't always so. Fifty years ago, Irish republicans were proudly Catholic; that is religiously, rather than nominally, Catholic.
That died out about the time of the hunger strikes in 1981. Then there were murals depicting prisoners being visited in their cells by the Virgin Mary. That's a bit embarrassing to remember now.
Unionism, the other tradition, has not secularised just as rapidly. The first First Minister of the devolved Executive, after the St Andrews Agreement, which made workable devolution possible, was a church leader and his party, the DUP, includes ministers whose thinking is informed primarily by their evangelical convictions.
But violence didn't arise from theological differences, but from these two communities never being able to trust the other in government. For 50 years, the Protestant community held power and managed many things to the disadvantage of Catholics.
But there were ideas at the heart of the beliefs on both sides, which were essentially mythical. Republicans argued that Ireland was, by rights, a single jurisdiction and that no part of it should be in a Union with Britain.
This is essentially a religious, or superstitious, idea. It stems from a conviction that a small island should govern itself and not be divided.
Yet we have another island next door which is three countries in Union and with one of them, perhaps, about to declare independence and break even further away from the others.
The equally tenuous myth of unionism is that the Union is always in danger, though it isn't. Never has been. This is mingled with sentimental ideas about the British Crown, which are difficult to explain.
Resolution, for the mean time, has been found by allowing the forces which cling to these myths to govern together on the compromise that there might be a united Ireland some day – if enough people vote for it; the unionists being assured that that is very unlikely to happen.
The problem, for now, is that the form of government created by this compromise produces inevitably a coalition between people of the two traditions, clinging to their mythical ideas. Republicans will never be persuaded that there can't be a united Ireland; unionists can never be persuaded that the Union is secure.
This excludes from power those who do not subscribe to either of the myths that the island should be one jurisdiction, or that the Union is always in danger.
Now some people will point out a huge omission in this analysis. They will say that Britain has been oppressing Ireland for 800 years and the problem is all their fault.
What they miss is that the 800-year argument does more to endorse the unionist case than the republican one. For, if Britain and Ireland have been interwoven that long, then we are integrally related and can not be separated without damage to both. Nowhere else in the world would anyone argue for a return to the status quo of the 12th century.
One can point to the deployment of paratroopers against civilian protesters and other atrocities as proof of British malice. Yet Britain declares itself neutral on the Union with Northern Ireland, while the Prime Minister pleads with people to write letters to Scotland asking them not to leave. When we are ready to go, he'll apparently be fine about it.
Now, any questions?