Remain didn't learn the lessons of their defeat. Instead of trying to create the conditions for a soft Brexit - and a potential return to the EU in 5 - 10 years time, they tried to derail it. Which ironically lead to a PM whom (I suspect) is happy with a WTO exit.
I also suspect that over the next 5 - 10 years we will diverge so far from the EU's body of law that it would be near impossible for us to re-join. The EU requires that you sign up to it's body of law in its entirety. In the ensuing join/stay out referendum, all the 'stay out camp' would have to do is point that out - and list all the things we'd have to give up/sign up to.
Remain knew when we were out, we were out for decades - hence their desperation to overturn the result of the referendum.
- If the EU becomes a federal Europe (aka the United States of Europe), I doubt we'll ever re-join - and a number of other EU states will hit the exit button at that point anyway.
- If the euro implodes - and the day of reckoning must only be 12 - 18 months off by now - the EU may have to undergo substantial reform. Only if it reverts back to to a free trade area would be we likely to re-join.
But they won the argument!
. . . or was that something else?