I creep back upstairs, past the bathroom, where I think I catch a glimpse of matching his-and-hers towelling robes – but I’m too traumatised to actually go in and check. At the very back of the flat, I come across a cramped, cluttered box room that appears to be my office. Hidden among the vacuum-packed mountains of Alice’s clothes, there’s a little wooden desk with a laptop on it, which displays my email inbox. It’s a work account, and as I scroll through, I find nothing but incomprehensible management consultancy-themed messages, most of them branded with screaming red exclamation marks. I can feel my blood pressure rise just looking at them.

Is this really what I do now? How have I not had at least one heart attack?

I try reading one of the emails, but I understand roughly one word in six. In the desk drawer, though, I discover something else entirely. Underneath another sheaf of terrifying business papers, there’s a slim cardboard folder containing a brochure for a company called Those Who Can. Flicking through, I see that it’s advertising a year-long paid course to train as a secondary school teacher. There are forms inside it – pages and pages of complex forms – and by the look of it, I’m about three quarters of the way through filling them out.

Future Me is obviously serious about this – about teaching – and for the first time, I feel a glow of pride at what I’ve become, rather than the usual blend of shame and embarrassment.

My throat tightens as I catch a glimpse of one of my longer answers on the form: I’m attracted to teaching because of my mum, the paragraph begins. But before the memories of her can take hold, the doorbell sounds.

I slam the drawer shut as I see Alice whisk down the stairs in a long dark blue dress, and all of a sudden the hallway is filled with loud voices and the frantic plap of cheek-kissing.

‘Hello! Hello! Happy Christmas!’ I hear her cry merrily. And then, less merrily: ‘Ben! They’re here!’

I walk downstairs to see a stupidly good-looking couple beaming back at me. They look like something out of an IKEA advert. The man is in jeans and rolled-up shirt sleeves, salt-and-pepper stubble covering his Captain America jawline. The woman is all golden hair and gleaming teeth and a very un-December tan. She is also heavily pregnant.

‘Ben! Happy Christmas! How are you?’

She pulls me in and pecks me on both cheeks over the exercise ball of her stomach.

‘Oops – belly bump!’ she laughs. ‘Sorry, I can’t help it these days!’

‘Yeah, watch out, mate,’ the man grins. ‘The little bastard’s kicking like mad at the moment – you’re liable to get a boot to the chest if you go anywhere near her.’