It wasn’t a fair vote because of deliberate disenfranchisement. UK citizens settled abroad weren’t allowed a say because the vote was only “advisory”. It could also be argued that 16-year olds could have been given a say in their entire future (vs, say, a choice of government for the next five years).
A minute sliver was also taken as a mandate to veer towards the most ideological extremes.I like to imagine many of the reactions if remain had gotten a tiny majority and in conclusion we had joined the euro and schengen.