What lies we tell our children, I thought. But why not? I hoped for Ryan’s sake that he’d always have someone there to catch him when he fell.

William was quiet in the car, his need for activity sated for the time being. Small boys were like puppies. Both needed lots of exercise every day and had basically two gears: go and stop. They had to be walked every day; otherwise they’d go stir-crazy and start tearing the house up.

His next engagement today was a fifteen-minute drive to Dollis Hill for a five-year-old’s birthday party. Jacob Pendlebury, one of his school classmates. A wall of noise greeted us as we stepped into the hallway and handed our coats to Jacob’s father. He gave me a welcome to the madhouse smile, eyebrows raised, as we went through to the lounge and William took his place cross-legged on the floor with a dozen other kids. Parents were arrayed around the edge of the room on a collection of sofas and kitchen chairs. The entertainer was a loud-voiced woman dressed as a jester who did magic tricks and got the birthday boy to join in as her assistant. She was good, but the cacophony of small children in a confined space was eventually too much for my mild Saturday morning hangover. After half an hour I sneaked out towards the kitchen, following the warm smells of home baking and fresh coffee.

There was a petite dark-haired woman in the kitchen – her face vaguely familiar from the school playground – carefully putting five candles on a Manchester United cake. Of course. We were in north London, so of course it made sense that Jacob Pendlebury was a Man U. fan. Growing up in Berkshire, I had supported Chelsea. Small boys supported winning teams. It took a few years to get used to the idea of supporting a local team that was consistently, miserably average.

‘The jester’s very good,’ I said.

She stopped planting candles and smiled.

‘She is, isn’t she? We booked her for my daughter’s birthday a couple of years ago, and Jacob always wanted to have his turn.’

‘Thanks for the invite.’

‘That’s no problem at all.’

‘I’m William’s dad, by the way.’

She nodded, returning her attention to the cake.

‘I know. We’re friends on Facebook.’

I felt a spasm of unease. That’s why her face looked familiar. How many people were there who knew me, even slightly, whom I’d friended on Facebook and then forgotten about? Some were actual friends in the old-fashioned sense of the word, but many were little more than vague acquaintances. Like this woman in her kitchen in Dollis Hill, with whom I had probably exchanged six words before today.

‘Really?’ I managed. ‘I don’t really use it that much, to be honest.’

‘Did you find that thing you were looking for the other night?’

‘What thing was that?’

‘That bracelet. You posted a picture of it.’

‘Oh, that. Yes, found it.’ I felt my face getting warm. ‘Silly, really, I don’t think alcohol and social media are a good mix.’