No going back is blindingly clear. Even if in a few years what was left of the country applied to join again, and every single EU government was in favour, it couldn't be to the status quo. We'd have to sign up the the euro, Schengen area, no special perks. "Out' means out.

Whereas "remain", and if next year it looked like a mistake there would be a bsolutely nothing to stop the British government deciding to get out. They wouldn't even need to have a referendum, I think, just a majority of MPs thinking that was a good idea.