I agree, by the way, that assuming people are 'thick" is a charge too easily bandied about. I expect the degree of "thickness' is pretty much the same throughout the entire population so there were about as many "thick" remainders as leavers.

My thickness test would be to see how many people asked themselves the "what if I am wrong" questions.   If I am a Remainer, for example, and believe the dire economic forecasts I need to ask myself if and why I would still vote remain if the forecasts turned out to be entirely wrong. Or if I was a leaver who was very concerned with immigration, I would need to ask myself if I would still vote leave if it turned out to be impossible to meaningfully restrict immigration.

I doubt if many people on either side reflected very long challenging their own assumptions like that, though undoubtedly there are those who did in both camps.