Forget compatible personalities, forget mutual attraction and even forget (gasp!) road frontage.
These days, the secrets to a successful relationship are all contained within a few simple practicalities. And we've outlined them for you...
1. You both use the same phone charger
This isn't about Android vs Apple.
This is, quite simply, about being able to stay in theirs and not having to worry about packing a charger on top of everything else.
(NB: If you don't currently use the same phone, but you both have a spare charger 'of the other sort', this is equally acceptable.)
2. You both use the same laptop charger
These are generally far bulkier than phone chargers, and so this is perhaps even more important than the above point.
3. You live on the same Luas line
Or at the very least, you both live near Dublin Bike stands. Ain't nobody got time for switching routes in this day and age.
(I know; I literally would not survive a day in London.)
4. You’re both into #cleaneats...
... or you both like to laugh at people who are into #cleaneats
5. You both share an irrational hatred of one particular ingredient
So it can be banned from the house with no disparity.
Or better still, you're both allergic to the same ingredient... or better STILL, you're both coeliac or lactose intolerant!
6. You hail from rival counties
Because being from the same county is boring – but rocking up to Croker on a matchday with a Dublin jersey and a Meath jersey, or Cork and Kerry, is just absolute fodder for press photographers.
7. You have a shared philosophy towards the snooze button
There are the up-and-at-'em types, and the ones who like to hit 'snooze' 20 times before actually getting up.
And ne'er the twain should meet.
8. You have similar tastes in Netflix bingeing
I mean, just imagine one watched Making A Murderer and the other didn't?
9. You share the same initials
Because everyone loves monogrammed shit, but half-price is always better.
10. You share a 'guilty pleasure' takeaway
And more importantly, you both fall on the same side in the Great 3-in-1 Debate.
11. And finally... you both prefer either red or white wine
Sounds simple, but it had to be said. Because only bajillionaires can afford to drink by the glass, in fairness.