When we met, my wife had one non-negotiable: the beach. I had one too: Estonia. She followed me there that first time the way you follow a friend into a restaurant with no English menu: trusting yet aware of the exit. Now, she may love Estonia more than I do. Our travel system is simple. Estonia every year, plus a new country every two or three. This year the new country was Ireland, which had sat atop both our lists since our honeymoon. We'd see the west of it by campervan, for the first time, with a one-year-old, in the...