When it comes to dieting, there is something very interesting - and actually quite satisfying - about the Christmas and new year period, containing, as it does, the binge and purge impulse in microcosm. First comes Christmas, its table heaving with gustatory delights - the mince pies, cheap chocolates, and multiple roast potatoes we would naturally have struggled to avoid in previous months. In late December the warning bells in our head are replaced by the sound of Noddy Holder yelling "It's Christmas!", giving us the perfect licence to suck down more brandy butter.

The bloating that results is less worrying than usual, because we know it's the ideal prelude to the next phase, the era signalled by the bells striking new year, when we put down the champagne glass, pull on the tracksuit bottoms, and convince ourselves we can become a new person. We will work harder, eat less, eschew alcohol. Eventually we will shed our winter skin, and emerge blinking into the sunlight, renewed, revived, redeemed.

Of course, this time of year is also a chance to look back and ask: did I achieve everything I wanted to last year? Did I lose as much weight as I would have liked? No. But I am lighter than last year. Did I get as fit as I would have liked? No. But I am fitter. I didn't succeed, but I edged in the right direction.

Thinking about this reminded me of when I was 17. I had just been turned down by a good university, and a mentor sent me a card with a Samuel Beckett quote: "Try again. Fail again. Fail better." I was mortified. What on earth was he trying to say? That I would keep on failing? That this was the start of a long losing trajectory? At that age, I couldn't understand that, on some level, we always fail.

Now I do, and it's comforting. In trying to be healthier, stronger and happier, none of us will be perfect this year - perhaps you've already fallen a bit short of your new year aspirations. If we can fail a little better, though, that might just be enough.