It is hard to understand how people can be so short-sighted and indeed nitwitted as to vote to leave a larger political and economic union, without the slightest idea of what was to happen afterwards. Or how politicians, with a hugely inflated view of their own country’s importance, can ignore economic and commercial practicalities in favour of an entirely unrealistic notion of sovereignty. No thought for how existing commercial relationships would be affected or how that would affect trade and employment. A ridiculous assumption that politicians and civil servants could set up new trade deals and would be better at it than those with practical experience.
I say this not to excuse HM Brexiteers — I think that both they and Sinn Féin (past and present) are bonkers — but to suggest that outbreaks of mass insanity can happen to anyone.