With each rigorous diet or regime of particularly committed exercise, I wonder if I’ve turned over a new leaf for good, finally choosing a life of discipline and rigour and its rewards over the addictive pleasures of immediate gratification. (Reader: I never have.)

But I had the same thought last year when, for the first time in a long time, I observed Yom Kippur. I’ve always felt obliged to acknowledge Kol Nidre, I think for the irrational reason that I love the cello piece by Bruch with the same name, because it captures a feeling that I associate with the tapestry of the lives of my German Jewish ancestors: strong, sad, powerful and powerless.

But my usual observance involves either popping in for an hour to the super-glamorous Orthodox St John’s Wood shul or lying on my bed in candelight listening to the Bruch on repeat.

As for my usual non, or very partial, observance of Rosh Hashanah, it has always reminded me of those terribly long and boring days children experience (or used to before the jamboree of children’s services), boredom I continued to experience as a young but dutiful adult without a religious bone in her body. Yom Kippur, whenever I observed it, was a riot of fevered imagining of the food I would eat as soon as I could, not a time to dwell on my sins.

But last year’s Day of Atonement and its unplanned observance turned out to be enriching and nourishing. A friend was going along to the Grassroots service — a collection of liberal-minded Jews in a tent in a Golders Green garden — so I jumped on the bus and met her there. I had recently turned 40 and thought I ought to renew my quest for meaning.

It was curiously soothing. Soon, I found myself engrossed in Jonathan Sacks’s Koren Yom Kippur machzor, only vaguely annoyed by all the standing up and sitting down. I read about the curious legal flavour of Kol Nidre, the contractual eccentricities that enable the breaking of any vows to God for the future year, so as to clear the decks for atonement and recommittal. I found Sacks’s commentary erudite, intellectually gripping and satisfying, and elegant in the way it bridged the spiritual, the theological, the ethical and the legalistic. It made me proud to be Jewish. No other religion’s holiest day would produce a text like that, so satisfying to the non-believer.

And so, cheered by the experience, I went home, but made the mistake of taking the bus and feeling an uncomfortable sense that I was being sullied, crowded in with gentiles on a night like that — terrible as that sounds. So the next day, I walked back to the Grassroots tent after cancelling a call with a literary agent I was due to have that afternoon.

The contrast with this year is striking. Like the high hopes of permanent change during a diet that makes you feel healthy and virtuous, I fell off the wagon. Something to do with the old reasons of effort and inconvenience; a failure to make the sacrifices, however small, required to clear my schedule.

The truth is actually a bit worse. The day before Yom Kippur, I kept a Sunday lunch date and then, instead of peeling off to go to shul, I stayed on and watched several episodes of Dinner Date, a poor man’s Come Dine With Me that Netflix has been pushing. I got home around 9pm from south-east London, in time to have a snack with my mother, who was just as bad as me, having come from her own English Sunday lunch.

The next day, instead of spending our time — just one day — being Jews and thinking about the rich terrain of atonement and the future, both of us got on flights. Hers was back to America, where she lives, and mine was to Sicily for a holiday. Flying with me was another Jewish friend, the composer Elena Langer who, like many who grew up in the Soviet Union, has even less sense of obligation to her religion than I do. Monday was the only date it made logistical sense to fly out and so we did; when I realised it was Yom Kippur, I felt a brief pang, then shrugged.

But it wasn’t the greatest feeling. Or rather, watching Dinner Date on Kol Nidre and flying to Sicily on Yom Kippur was more obviously pleasurable than sitting in shul, but there was nothing to distinguish it from every other weekend or holiday. More to the point, I lost the mixture of intellectual nourishment and wholesome belonging that only Jewish observance on Yom Kippur offers.

Next year I will get back on the wagon. After all, I’ve spent the last 20 years rebelling against the strictures of my youth, indulging every whim and comfort. Now I’m ready for something a bit more bracing. And being hungry for one whole day isn’t anything a perennial dieter can’t handle.