Ttb
Also on the note of the Black Death surely that was a good thing despite the massive loss of life?
I'm guessing you've been reading "Inferno" by Dan Brown, where the anti-hero plots to unleash a nano-plague on the human species with the intention of getting rid of 2/3 of the population (as did the Black Death) for the greater good.
I'm hoping that Brexit will not be quite so effective.
Your post does, however, shine a light on the altruism - "pain for future gain" - of Brexiters. My suspicion is that those caught up in the historical event of the Black Death at the sharp end (dying in agony; walled up in their homes to die; watching their loved ones die) would fail to be consoled by a time-traveller from the future explaining that some historians posit the Black Death as making the Renaissance possible (for the descendents of those that survived).
Likewise, I suspect that much of the altruism of the Brexiteers rests upon a calm assumption that they will be exalted from being on the sharp end of historical events. Why? Well, I think it is a. born of the experience of many decades of political calm (the "It will always go on being like this" fallacy,) and b. the historical fallacy: no-one ever imagines themselves as being one of the voiceless, nameless, wiped-out of history, do they? History is told to us - by and large - by the survivors, and we read it as 'survivors'.
(b) has a caveat: I suspect one or two of us on this thread don't have that calm assurance - having either lived through bad historical and political experiences, or having relatives (even long-dead relatives) who weren't historically so lucky.