I know all about two-tribes mentality - I grew up in Northern Ireland, after all.
Not only that, but as the child of a so-called 'mixed marriage' (how my late parents hated that term) who was raised in the Protestant tradition and attended a school which totally embraced that ethos, as a young teenager I lived in dread that religion would come up for discussion in class and that my Catholic credentials would be exposed.
To discover, therefore, when I crossed the water to university in England at the age of 18 that nobody knew what religion anybody else was - and cared even less - was such a revelation. A lightness-of-being moment.
Ultimately, however, my background was a blessing, for it gave me something not many Northern teenagers were lucky enough to have back in the early 1970s - perspective. And a sense of understanding because of my constant access to 'the other side'. For that 'other side' was my own family - my paternal grandmother, my aunts and uncles and all of my cousins.
Two-tribes lands are disconcerting places for those born and raised there, but also for those passing through and unsure of which path they are treading at any particular time. Say the wrong thing and who knows what the reaction might be.
I can still recall the look on the face of an Israeli civil servant many years ago, while sitting drinking an aperitif with her in the lovely garden of the American Colony Hotel in Jerusalem, when I said I wanted to visit the West Bank.
"What?" she almost shrieked. "No, no, that wouldn't be possible," she said. It wasn't, apparently, part of my pre-arranged, Israel-only, itinerary. No problem, I told her. I'd get a taxi myself, even just as far as Bethlehem, since it was only a few miles away.
She was horrified. Utterly horrified.
Which brings us to the two-tribes territory of Israel and Palestine. And to Colum McCann's magnificent novel 'Apeirogon', which this week made its way on to the Booker longlist.
What a book it is. With its 1,001 chapters (some only a sentence in length, others myriad pages) this construct is based on the '1,001 Arabian Nights'. This "hybrid novel", as McCann himself has called it, is inspired by the real-life stories of Rami Elhanan, a former Israeli soldier who served in the Yom Kippur War, and Bassam Aramin, a Palestinian from Hebron who served time in jail for throwing a grenade at an Israeli tank.
Tragically, both lost young daughters to the conflict but, hearteningly, and in a way that is so uplifting as presented by the magical prose of McCann, the two men have become close friends through their work together as they strive for peace and for a greater understanding of what makes each other's tribe tick.
There's no judgment here. No one is right and no one wrong. Both men are simply accorded the right to be heard. And in a novel so understandably full of grief it is comforting - inspiring even - to find such commonality and empathy. And such beauty in the power of friendship.
Bassam and Rami are the very antithesis of the two-tribes mentality; they understand each other.
Indeed, in one beautiful moment when they are asleep together on a train as they travel through Germany from one speaking engagement to another, you actually glimpse more than that. For as Rami's older and larger body supports Bassam as he sleeps, you see more than support, more than understanding. What you see is love.
'Apeirogon' is mesmerising. And an important novel for our times.