Many Brits thought this before the election. It was pretty much the exact same scenario as Trump winning, it was such a silly idea that no one could even believe it would happen. Unfortunately you just get a biased view of the situation from getting all the info and conversation from online
The problem is just over 50% of our population seemed to be wearing rose-tinted goggles of back when we controlled over half the world's trade...
They failed to realise the reality that we relied on the EU as much as it relied on us, and cutting ourselves off from our primary trade partners was a plainly stupid thing to do.
There was also the racists who saw it as a way to get rid of the "foreigners", not realising many of these immigrants weren't from the schengen zone, therefore wouldn't be "sent back", but that's a different story.
Slightly less than 50% of the country could've told you that was gonna happen before we were forced through the motions.
Should've been common sense that blocking ourselves off from easy access to trade with our primary trade partners was a bad idea, even more so when you consider the privileged position we had in the EU based on our former standing as a world superpower that we were tossing away for nothing.
I'm referring to the ~48% of remain voters that did turn out.
Not counting those that didn't vote (if thry could) because they're arguably more ignorant than the Brexiteers, complaining now when they didn't speak up back then.
None of the current major parties (and that's inclusive of Lib Dems) are totally commited to saying that they'll definitely and decisively go through the motions of rejoining. At least not that I'm aware of.
None have to confidence that it'll get them more votes than lost. Which is fucking frustrating. Especially since Labour seem to very quickly becoming much of a Tory mirror of late.