There ain't no such thing as a free lunch.
You've probably learned this already. When someone offers you something for free, you'll find that you're paying somehow. It's a fundamental principle of life, and if you haven't learned it yet, then you just haven't lived long enough.
That's not to say you should avoid taking advantage of the free lunch. It's just that when you're offered something for free, you should look into what it is you'll be giving in exchange.
For example, Google. It's a free search engine, paid for by advertising. I understand and accept this, because the benefits I get are far greater than the annoyingness of the ads (Google, wisely, allows only text-only ads).
Other trade-offs might not be so good - for example, I'd like to read the free version of Forbes magazine, but they want me to turn off my ad blocker, which is what prevents me from being hit by malvertising (and Forbes has previous on this).
I'm hearing from Brexiters that we get a free lunch if we leave the EU. We get to keep the hundreds of millions of pounds that we currently kick into the budget, we get to control our borders, we can ignore the Brussels directives and we get our sovereignty back.
That is such a free lunch, that I immediately want to know, OK, what am I giving in exchange?
If you look at Switzerland and Norway (and Iceland and Liechtenstein), you find out. If we want to continue to trade with the EU on the basis of "no tariffs, no quotas" then we'll have to continue to contribute to the EU budget, we'll have to agree to free movement of labour, to conform to the Brussels directives and so the sovereignty that we get back, we'll gave to immediately give up again.
Or we can decide that we don't really care about exporting to the area that currently takes half our exports. Which isn't on because we're a trading nation. Without a free trade association, there would, for example, be tariffs of 10% on cars exported from UK to EU. Now imagine you're Ford, or Toyota. Where will you want to build a factory, the place that gives you free access to the 500 million consumers in the EU, or the place that gives you 60 million consumers in the UK, and adds 10% to the cost of exports to the 500 million of the EU? That's why we'll want to join the European Free Trade Association
So it looks to me as if the only gain we get, will be that we'll be freed from the need to send 73 MEPs to the European Parliament to represent our country, we'll be freed from having to argue about changes in EU regulations that affect our country, and we'll be free from the veto that we currently have on additional countries joining the EU. We'll be standing outside the room within which 27 countries decide stuff that affects our future.
The free lunch turns out to be expensive.