In February, my sister and I took the ferry from Dover to Dunkirk. On the way back, I noticed there was a deal: spend €150 (£130) in duty free and get a free day-trip ticket. If you love Toblerone and know anyone who smokes, you can spend that without even blinking – and so it came to pass that I was back on the ferry within a month.

This was when I started to perfect the art of the day trip, even though I didn’t yet realise this would be the beginning of a beautiful loop. You arrive and go to the........

© The Guardian