At 67, Dame Helen Mirren rarely puts a foot wrong in the fashion stakes.

At 67, Dame Helen Mirren rarely puts a foot wrong in the fashion stakes. Photo: Getty Images

The last time I wrote about Dame Helen Mirren, I received an elegant letter in response from an eminent plastic surgeon. I'd been mouthing off about how she proved you could look totally great at any age (she's nearly 70) without plastic surgery.

His point was that all she proves is the difference between really good plastic surgery and the horror-show version that leaves people looking like catfish in a wind tunnel.

That was slightly depressing because I ain't never going to be having any kind of it so I'll just have to hope all the downward dogs and fish oil do something for me.

Or I'll just grow Shar-Pei wrinkly with style like Mick Jagger and Georgia O'Keeffe. Although the key thing about those two is that their marvellously weathered heads sit (or sat, in Ms O'Keeffe's case) atop very slender bodies.

I think you've got to have proper architecture of bone structure to hang face crinkles off for it all to work. So, I'll let you know how I get on with the ''five:two'' fasting diet in that regard. At the moment, my wrinkles are more like rough frosting on a currant bun.

Meanwhile, I'm just going to enjoy gazing at this picture of Mirren. I no longer care whether she's had surgery or not. She's an actor, they're under a lot of pressure to keep the face close-up ready, whatever. All I'm interested in is how magnificent she looks here.

She doesn't look ''young'', that's not the point or, I think, her goal. She looks like herself, just a more mature, polished version of it: beautiful, poised, confident and elegant. She looks grown up.

Grown up is a concept I've long been obsessed with as a positive way of thinking about getting older. I make lists of it in my head (which I have considered making into a Twitter tag but talked myself out of it in the interests of ever getting any real work done). Things like this:

Grown up is when: you never run out of loo roll; you're on the second washing machine you've bought yourself; you read the money section of the paper before the travel section; you have a week's worth of dinners you can cook without referring to a book; you know where your insurance documents are; there are several restaurants at which you order without looking at the menu; you have a favourite brand of gin.

Grown up is also having the confidence to look this relaxed in a drop-dead bright-red evening gown.

Mirren would have looked terrific in a blue dress, or a black dress, but how fabulous to shout it out in scarlet, the colour women over a certain age aren't ''supposed to'' wear? Sod that.

And the overall effect is further heightened by the mischievous, knowing expression on her face. She knows she looks great and it amuses her to see everyone's reaction to it.

But putting all that aside, in pure style-analysis terms, what I adore here is her hairstyle. Remember when Princess Diana got soaked at the outdoor concert in London and looked better with drowned-rat hair than she ever had before? It's that look. And with very simple pared-down make-up, it gives the knockout dress - and killer jewels - even more impact.

So thank you, Dame Helen, for being an inspiration at the start of this year and helping me to stick to my resolution not to obsess negatively on growing older but to enjoy growing up.