At a recent "The Oldie" lunch, Simon Jenkins gave a talk about his book
A Short History of Europe.
On the topic of Brexit, during his research, Jenkins found that Britain had ‘left’ Europe on no less than nine separate occasions and had rejoined eight times… wait for it! It just goes to show that the only power greater than history is geography. The constant back and forth, said Jenkins, was an inevitable result of Britain’s position on the edge of Europe, doomed to be half-in, half-out.
Source link here, but no more details there, I'm just providing it for "no link, don't believe it" Brigade
https://www.theoldie.co.uk/blog/nine-historic-brexits-at-the-oldie-literary-lunch