It’s late on a sultry August night in 2018 and I’m sitting on the outdoor terrace of the Peninsula Hotel in Paris, sipping a ridiculously priced mojito and people-watching the assembled beau monde. Trendy young women laugh and clink glasses with girlfriends like in a scene from Sex and the City, older, well-heeled looking couples talk quietly together, while younger, loved-up twosomes flirt and canoodle like there’s no tomorrow. Me? I’m there with my son, Nick, then aged 29, and we’re rounding off what has been a magical three-day trip before flying home the next day. “I’ve been invited,” I had told him some months earlier, “to travel from Venice to Paris on the Simplon-Orient-Express. Would you like to come with me?”