Re: Remind me...
Depends what you want. Some people voted on immigration levels, some people voted on economic grounds, others political or constitutional. Remeber that UKIP were founded by economists and were originally about leaving the EU to do freer trade (as well as opposition to the Euro). It became a more socially conservative / anti-large-scale immigration protest party later.
That's why some people campaigned to leave the political bits of the EU and join the EEA, and others wanted to leave and have unilateral zero tarriff access allowed to anyone in the world and others wanted some kind of special deal that the EU were unlikely to offer.
The real answer is that a small minority believe strongly in the EU, and another small minority really disllike it. But quite a large majority aren't fans, and definitely don't like the political bits, and were willing to be persuaded on the grounds of whether it was more hassle to leave than to stay and put up with the bits they didn't like.
One economic forecast from the EU (also pretty much agreed with by the World Bank) was that if we'd stayed in, our population would have gone up to 85 million by 2040-2050 and our GDP overtaken Germany's by the early 2030s. Now I'm pretty sceptical of those kinds of long-term forecasts - but it's interesting to ponder that and wonder who the winners and losers would have been from that scenario. Personally I don't think that would be politically sustainable - countries who add 30% to their population over a couple of decades tend to suffer high instability and massive social changes, to go with the ecomic growth.