Well, what will happen in the UK in the next couple of weeks/months/years might just be enough to show by example what the good bits of being a part of the EU are.

The big mistake the brexit voters made is that they thought that the UK as it was before the EU would have been a better place to be in today if the EU had never happened. Contrary to their belief the sum is a lot more than the parts but explaining that to the electorate is a challenge that modern politics (soundbites and tweets) is badly equipped to deal with.

Much easier to push the emotional buttons of xenophobia and economic malaise due to 'others'.