You hear this argument all the time, and it sounds superficially appealing doesn't it. Britain standing proudly on its own, standing for freedom and free enterprise, making its own way in the world. "We've were doing very well before we joined the EU" etc etc etc.
The problem with this rose-tinted image is it's not of Britain's recent past, it's of Britain 100 to 200 years ago. People would do well to remember our more recent past before yearning to go back to those idyllic times:
The 1960's and 70's, for example: Highest unemployment in Western Europe; strikes; power cuts; inflation; 15% interest rates; dismal productivity; shoddy workmanship; pitiful product quality (Austin Allegro anyone?); terrible public services (10 weeks to get phone line installed); awful customer service. I could go on.
That was the Britain before joining the EU. We were "the sick man of Europe".
Whilst I don't suggest that the EU has on it's own fixed all of those things for us, nevertheless, they go to show just how capable we are of fucking up our own country without the EU meddling in it. We were in a terrible state when we ran things all by ourselves.
There's no guarantee at all that a Brexit vote won't deliver a short term dip in living standards, followed by a long term ongoing decline further still.
(For the avoidance of doubt, I have finally made my mind up once and for all and I am voting Remain.)