From a UK person: we are also confused and would like to understand.
In the end, it is all politics. Former PM Cameron thought he could solve divisions within his political party by promising a referendum, a spiffing wheeze that came spectacularly unstuck. There is no political way back from that, although Nicola Sturgeon in Scotland is trying hard (also, Putin is hoping to fuel Scottish nationalism through a propaganda operation in Edinburgh). The Irish, both North and South, are completely discombobulated by it all (to our friends in North America: please don't start sending them guns again, it's not going to help).
I am hoping that when negotiations start, common sense will prevail. It is not helping that France and the Netherlands have elections coming up in which the far right are featuring strongly, that economies across Europe are stagnating, that Greek finances are getting worse not better, that Italy's government is a caretaker, that Merkel is also up for reelection this year and that Erdogan in Turkey is doing his authoritarian best to create chaos to the south.