I don't think anyone did. Brexit meant different things to different people, above all it meant change to most people, whether you call these the left behind, the stupid, the gormless, patriots, racists, whatever there was a chance to change things which 17.4 m voted for. Brexit its clear, especially if a hard Brexit, will become a catalyst for political change not just in the UK but also in the EU. Some will see Brexit as an idea whose time as come, others as a self induced injury/mistake, the fact remains (forgive the pun) there is no going back now. There will be hiccups in the economies of both the UK and the EU, but these will heal overtime, probably fairly quickly, but as usual with such changes there will be winners and losers.
Brexit is essentially about (and always had) the potential for Political change; Boris perhaps more than most recognised this and chose the right side. Boris is probably hoping for some change in the Irish position on the back-stop which will convince the EU to make some concession that he can get through the HoP; he may even suggest that if they play ball then in the next five years he will get the DUP to agree to an United Ireland vote (assuming he's still in power!) or at least a vote on a potential Confederation of Irish States within an All Ireland remit, with the UK backing the proposal with some of the £39B, if it eventually becomes no deal ,or if some sort of backstop is required.
Boris may also try to push the SNP to press the self destruct button and go for a 2nd Indy ref, but on the wrong basis, lose for a second time and kill independence stone dead, this time for more than a generation. Or, having been successful in an independence vote the SNP realises the loss of Fastlane, the change in currency and the withdrawal of many English businesses, will off set any gain of Scotland remaining in the EU (if it was able to do so).
If there is no last minute deal Boris's last card is to offer a GE on the eve of Brexit, even if he survives a no confidence vote.