Why leave EU?

A LOT of people voting in the Referendum will not remember our pre-EU days. They won’t recall the newspaper headlines of those days; “UK a Basket Case,” “UK the Poor Man of Europe,” plus many more telling us what poor shape we were in. 
This was when we concentrated our economy on the markets the Brexit promoters are proposing as our bright new future. We also traded with the EU via the same type of Trade Agreement Brexit is suggesting we have after we leave the EU (We have been there before!) I remember the headlines. 
I also remember inflation being a crippling 20 per cent. Brexit doesn’t mention that we already trade with the countries they are proposing as our new venture. However the countries being put forward as our saviours are changing. 
The USA is in negotiation with the EU (three years and ongoing). Australia and New Zealand have recently signed the TPP (Trans Pacific Partnership) Agreement with the USA and other Pacific countries after seven years of negotiation. 
India is directing their economy towards Asia. Canada has stronger economic ties with the USA and others through TPP and is negotiating to get closer to the EU. We have gone from being the economically weakest of the developed European countries (fact), to being one of the strongest (fact), and this is due to being in the EU (fact). 
Why leave the EU to go back down the economic route that was so bad that we had to join the EU to rescue our economy?