Bear in mind the UK use Sterling and the RoI use Euros. A NI person could work in RoI and be paid in EUR but pay rent etc in GBP. Obviously the reverse is true a RoI citizen might work in NI and be paid in GBP but needs EUR to live on. All a bit of a pain and of course the bank's exchange rate doesn't help.
It is easy to poke fun at those at the edges but I think on balance a bit of sensitivity might be warranted here. Little Britain might think that they (we) have some problems to deal with wrt Brexit.
I would suggest that we might look at NI and RoI and at least try to understand that the really important issues are right there - those issues and our responses to them are the ones that really define what sort of people we are now and will be in the future.
The rest is accounting.
We (UKoGBnNI) are still in the EU for now - next year we sort of leave (ish!!)
I've always whinged about those self serving bureaucrats in Bruxelles. Some of them are our own home brewed UKIP lot. It says a lot about democracy that UKIP or the SDP (int al) can even exist.
We'll see what happens to the little old UK post Brexit - it will be written up as both a triumph and a disaster and yet I suspect life will tick on, much as before.
GDPR on the other hand: that is important and worth paying attention to.