On Sunday morning I notice a flat black rectangle, wrapped in plastic, sitting on the kitchen table. It’s a brand new piece of luggage, a reminder that the middle one is off to America, to seek his fortune in the land of his father.

For a long time, while his trip was in the planning stages, the departure date moved in step with the calendar: it was always three months away. It continued to do this in my head, even after plane tickets were purchased. He made his preparations; I made none. My wife comes downstairs, coughing.

“I’m so ill,” she says. “I need to send you out.” She writes me a supermarket list with medicines at the top. I add the word “wine” to the bottom and, after some thought, “beer”.

An hour later, in the middle of aisle eight, I suddenly find myself in distress: I’m holding something I cannot see because of the tears in my eyes. To bystanders it must seem as if I am weeping over the price of a bottle of cough mixture. Later, consulting the receipt, I realise this would have been entirely justified. I paid less for the wine.

I recover myself and head for the checkout. The woman seated at the till recognises the customer in front of me as her son’s old maths teacher. Her son has just received a PhD, she says, and she wants to thank everyone who made a difference in his life. The teacher is visibly moved. I think: are you people trying to set me off, or what?

The two shopping bags feel unbelievably heavy as I lift them on to the kitchen table.

“What’s wrong with you?” my wife says.

“I’m freaking out,” I say.

“Don’t worry,” she says. “He’ll be back.”

“You say that,” I say.

She points upward, towards the youngest one’s bedroom. “Maybe you could change his overhead light today,” she says. “He claims he can’t see.” This is very like my wife – inserting irrelevant strands into the narrative in order to distract me, potentially through electrocution.

“Do you have a replacement?” I say.

“I do,” she says. She leaves the room and returns with a frosted glass globe on a flex.

“Fine,” I say.

“I’ll get the ladder,” she says. The new fixture presents an immediate problem.

“It’s meant to hang from a hook,” I say. “But it doesn’t come with a hook.”

“Do we have hooks?” my wife says.

“Not big enough,” I say. “I’ll have to go out again.”

As I walk down the road I realise why I’m so worried my middle son will go off to another country and never return: it’s because it’s exactly what I did, 30 years ago to the month, when I first came to the UK. I don’t just feel sad; I feel guilty. Then I think: pull yourself together; you can’t have a meltdown outside Wilko.

By the time I return with the hook, the youngest one is lying on his bed, and I am obliged to work over him.

“Is this safe?” he says.

“Time will tell,” I say. “How are we for length?” I hold the end of the wire up to the ceiling so that the globe hangs six inches above his knees.

“Bit higher, maybe,” he says.

“It’s easy to trim too much,” I say. The middle one pokes his head through the door.

“What’s up?” he says.

“I got you a present,” I say, pulling a UK-to-US plug adaptor from my pocket.

“Cool,” he says.

“Wilko has them,” I say. “Who knew?”

The next morning the middle one’s new bag is lying at the foot of the stairs. Unfolded and packed up, it’s enormous; the kind of thing you would order if you needed to dispose of not one, but a pair of dead hitchhikers. My wife is giving him a lift to the station. When the time comes, I carry the bag out to the car.

As I hug him goodbye, I take a deep breath to make sure I can iron the wobble out of my voice.

“Don’t forget to come back,” I say. I have a memory of my mother saying the same thing to me 30 years ago.

“I won’t,” he says.