Some of us may have seen the footage from Channel 4 News last night depicting various British people attempting to draw the Irish border. I don't think it's entirely coincidental that the guy at the end who showed the greatest understanding of the complexities of the issue was the one who made by far the best attempt at drawing it.
During the run-up to the Brexit referendum in June last year, some Irish politicians such as Enda Kenny did point out that the border would cause major complications in the event that the UK voted to leave the EU. They were invariably told to shut up and stop being "offensive".
In my experience, there is a significant number of British (especially English) people who have never cottoned on to the relationships between these islands. Many are not precisely sure of Northern Ireland's position within the UK. Some seem to think that the Republic of Ireland is in the UK. In that light, it's no surprise that the NI/ROI border didn't feature as an issue in the campaign and - without actual evidence - I'd hazard a large bet that those who voted for Brexit were the ones who were by far the more ignorant about it.
Well, sit back, my dear Brexiteers. Over the next few weeks, ye'll learn more about the NI/RoI border than ye learned in your whole lives.
EDIT: Thanks to Deadlock for highlighting this:
The Brexit minister David Davis thinks the Republic of Ireland is part of the UK