Yes we seem to forget the whole point of the EU is to stop wars like that ever happening. It started by not allowing one country to amass a large amount of steal to build warships for themselves and instead insisted that it needed to be shared (I am paraphrasing). They only treat us like crap as you put it, because if they don't and then other countries leave, well it could bring back the bad old days and another war. That's the reason, its up to us to make sure that future never happens, to make sure millions need not loose their lives needlessly in another war ever again! Yes the EU is not perfect, but it's ideals, which is basically stopping another war needs to remain.
We threaten to disrupt that peace, just look at what Brexit is doing in Ireland already, I for one am ashamed to call myself British with such a selfish yet also self damaging endeavour called Brexit and I can never be part of it.
We are even breaking up our own union over it, as 2 of the 4 countries voting remain were ignored.
