Here’s what happens when you turn forty-five. You realize you will only ever read so many books — how much time have you got left for reading? — and you had better only read the good ones. There are only so many movies, so many trips, so many new friends, so many family barbecues with the sun going down over the long grass. It has always been this way. Finite. But at forty-five you realize it.

Your daughter will go away to Montreal for her first year of university, and briefly her excitement feels like your own, you are filled with it, and then you realize that it is not you going to university in a new city for the first time. You will never go to university for the first time again. You will never go to Montreal for the first time again either.

And worse, your daughter has grown up. Your daughter is a beautiful young woman with the whole world in front of her, and she is striking out on her own.

You and your husband and your nine-year-old son will feel like the house is too big. You will decide a trip is the thing. You will think Turkey, you will think the southern States.

We could go back to Cuba. Cuba could be over, you think, very soon. You’d been to Cuba eleven years before, and here is your fear: What if it isn’t new? What if there comes a time in life when nothing is new?

Not so much, is that all there is? Rather, is that all there was? And: I want more.

Being a tourist, if you are not careful, will start to feel like a familiar experience, no matter where you go. Here is the heat. Here is the beach. Here is the same broken English and the same hard sell on the streets. The same silver and turquoise jewellery, the same bongo drums. The eerie azure of a tropical ocean is the same everywhere, and that palm tree — they just move it around. It’s the same palm tree, you are sure, they had on that beach in India/Florida/Tasmania.

There might be more behind you than ahead. You realize at forty-five that there is no now. The now is always infiltrated by the past. Now is swallowed up. Forty-five is a fulcrum. Before and after have gripped fists at the fulcrum of forty-five, and they arm-wrestle, and gone wins, hands down.

A bus ride to the Bay of Pigs. You’ve bought a book of Che Guevara’s essays and read about his first meeting with Fidel Castro. How they stayed up all night talking about the revolution. How Guevara knew, by the time dawn broke, that the revolution was a cause for which he was willing to die. He was twenty-seven.

My husband, Steve, and my son, Theo, are in the row behind me, and Steve has taken out the jar of peanut butter and a sleeve of crackers. He passes me a cracker over the top of the seat.