Greta, The average man on the Street" will be a different man or woman on every Street in this UK. All to varying degrees will listen to news reports, watch TV when analysis (although bias if I recall in favour or remain) is constant and again, if I recall negative and scaremongering. Those varying average people in the street who did vote with their instinct, heart and you failed to mention head, and obviously optimism for the future, or even clinging to what they know, are all of us. I am average when in my circle of friends and neighbours, you are average when in your circle of friends and neighbours. Realising that one does not have to be a rocket scientist to be able to see that the EU, is bringing down the EEA Country's, like Greece, Italy, and polarising politics into extreme views, or that we have just gone through a long period of austerity because the Euro failed from 2008 to just recently really. Greece has, is on it's knees, Italy is on it's knee, high levels of unemployment through the EEA Country's. The man and woman in the Street us, even the rocket scientist, will either see or refuse to see, we cannot all make the same decision about the evidence before us, that would make us automatons.
We the average man and woman in the Streets, also saw and heard, analysed, synthesized and evaluated (we all might not have been able to label that process, but that is what we did) that the EU was being difficult with the UK and saw and heard that Cameron their PM was treated like s--t, whilst claiming a victory with the EU adjustments he sought, he actually failed spectacularly, since they would not deal, or they suspended or they prevaricated just as they are doing now.
As you might think some average men and women in the Street, might not read the Parliamentary papers, although some might, we can all mostly read, and mostly we are educated to a greater or lesser degree, some might even have been to University, others might have worked their way up the greasy pole of the "corporate ladder", others might own their own SME or MME, some could be ill, some could do a myriad of types of work. I could go on. Some who can might just not be interested, others who find it more difficult but have a great interest might make the effort to find information. One cannot generalise.
I have said this before too, generalisation is the most destructive group labelling, and othering that one can be engaged in. It is dangerous and indicates an ignorance born of more than a lack of education by the generaliser that goes with arrogance as far as I am concerned.
So as an average woman in the Street, I can categorically say, that I have been weighing up the EU for years, I have been watching the referendum developing as the EU co-operation declined since 2013. No one in the UK or even in the EEA could have failed to notice, not even us the average people in the Street, that Brexit was inevitable. If you missed that possibility of Brexit, and it seems some did, the way out is to discredit those who did anticipate, analyse, synthesize and evaluate and attempt to down grade them as the “average man in the Street” therefore he must be wrong because, well as you put it he is only ”the average man in the Street” It is clearly unbearable for some to acknowledge that those who saw something they didn't, must be unable to analyse or read Parliamentary docs, or watch Parliament on the Box....or they must read the Sun, so! Disgraceful, othering...shame! I should say that not all of those who prefer to remain are engaged in attacking those who prefer to leave. Some people are accepting of the majority vote system in this Country and have got behind it. One cannot generalise.
For a time I travelled on the train between Manchester Picadilly and Chester each morning, the carriage was empty usually between Piccadilly and Marple, a scruffy, man with greasy long haired, unshaven, down at the heel shoes, carrying a brief case, there was often a slight wiff as he walked past to his seat. Every day he took out of his brief case the Financial Times. It intrigued me, I never did pluck up the cheek to ask him, because that would have been arrogant. So a good adage, that my Mother and Father taught me was never, never judge a book by it's cover. I offer that to you as words of wisdom that you would do well to take on board. Particularly when generalising about the leave voter. Our 'averageness' makes us powerfully invisible.
Brexit is an evolving negotiation, we are walking on new ground, no one is absolutely certain about how things will pan out...but why would you think that your Government would not be writing Parliamentary advice research papers on every subject, every departmental involvement, every Statute being reviewed and amended or re-written. That the permit system for financial trading would not have an emergency system in place in case of non co-operation by the EU, which is highly likely. Come on!! There is of course the extreme political element to all this, a high degree of self interest's and I sense a lot of destructive opportunism in the form of Political activism and some spectacular narrowmindedness. Only in some of course.