If everyone is special , no one is special.
The Brexit delusion is that only the English are exceptional. Hence people stil bollocking on about Dunkirk, the Spanish Armada, two World Wars and one World Cup and God knows what else.
WRONG... It doesn't matter if a people are exceptional or not, what matters is they believe it. That belief fuels social capital, that can see a nation grow together and develop the resilience to deal with problems and crises.
To believe the way you do is a trap; it strips away peoples hope and belief in change and turns them into an even more selfish person and that person can in the short term, be relied on to see the benefits of an empire (especially so, if they have the wealth and education to enjoy the benefits of belonging to an empire). But, come a problem or crisis large enough to trigger the selfish people who have zero social capital, then an inevitable scientific calc will see serious disorder.
Brexit is a chance for the UK to reset itself, before its too late. But, the establishment don't want to lose their imperial connections.