It's not that we massively care about celebrity divorces. We don't. We much prefer it if the divorce in question is closer to home so we can get all the facts straight from the horse's mouth, or at least the horse's friends.
Relatable detail is everything, because this is about Us.
We are divorce forensic scientists sifting for clues. Why now and not then? Why choose Her over Her?
We like to identify fault lines: working in different cities/going on holidays with your ex-wife and the children/being a total killjoy and then putting on 10 stone.
It's all about gathering evidence with which to shore up our own relationships in preparation for stormy seas ahead.
That's what we tell ourselves.
Also, we are nosey.
Of course, there's an element of fear driving this prurience. "He came home one day and said: 'You've Let Your-self Go and I am moving in with a 28-year-old Pilates teacher."'
That's a sentence that'll make you rush upstairs and start tweezing your chin hairs there and then.
Almost everything that's thrown up by other people's divorces resonates a bit with married couples.
Most of all, divorce watching makes us feel good about ourselves.
It was all about the children. It was all about work. We never talked about anything apart from who was paying for the boiler repair. No one was interested in him - only whether he'd done the things on his list.
Other people's marriage breakdown stories are sharp reminders, courtesy of the people who left it just too late.
Put away the slanket! Stop calling each other Tubs! News of divorce is our cue to take those rapid state-of-the-marriage exams.
Are we having enough sex? Should we kick the dog out of bed? When you said you can't eat another of my Thai curries, were you serious? And so on.
There's also the pride issue: we can't believe we didn't see it coming. We need to go over another couple's divorce from every angle until we are reassured that we sensed the sands shifting at the (as it now turns out) fateful New Year's Eve party, because otherwise that means we are equally vulnerable.
And we like to establish whodunnit (even though there are two sides to the story, yes yes, blah blah) so that we can feel furious with righteous indignation on behalf of the injured party.
But, most of all, divorce watching makes us feel good about ourselves.
I don't mean good good. I mean grateful for what we've got. Very slightly - and much to our surprise - smug.
When you are sitting at home for the umpteenth night in a row, eating ham and watching TV in silence, you might feel life is passing you by.
But in light of a divorce, any divorce, you can reflect that at least you are a unit. At least there is someone to get you a cup of tea, who knows what you are thinking, just by looking at the back of your head.
And while everyone else out there is sexting younger lovers, and setting up secret bank accounts, and blowing their children's university fund on lavish mini-breaks with Angela from the office, we can feel reassuringly solid. Other people's divorces are good like that.
