I love being the very tale end of the baby boom. When I was in my late thirties, everyone suddenly noticed that you could be sexy at forty. (Well, duh.) Now I'm in my forties (early forties, thank you), and I see in the Globe this weekend "Foxy 50". So when I get to my fifties, they, too, will have been "discovered". Because before we got there, they had nothing to offer, of course.

Under this headline are the beginnings of two columns, one by Sarah Hampson "On why we're having the best sex ever", the other by Marni Jackson, who "Wonders when we get to hang up our thongs".

I liked them both, but I liked Marni's best. Having said that, why do I feel the need to first state that I have a great sex life, thanks, that only Saturday night I'm quite sure I woke the neighbours with erection-rousing cries of ecstasy? Because I did, she says with a shiver of happy memory. Yes, indeed.

And yet.

Jackson says it well: "I don't see this carnal colonialism as a liberating trend. It's not about discovering a new and grown-up life that might suit the dignity, appetites, and experience of an older woman. It's about fear of aging."

Bang on, Marni. Er, in the British sense, not the American.

She continues:

It's still the same old story: Women must define themselves first and last through their sexual activity.

But what if they would rather reinvent urban environments [we'll miss you, Jane], or run countries, or protest againt the war in Iraq, or do nothing but sit around in their fleece robes finishing thosand-piece puzzles? [Older women] have earned the right to stay in the race, or withdraw, and still have our respect and curiosity.

I enjoy my sex life, and enjoy the attention I can still garner walking down the street. (Not from 20-somethings, who are generally as disinterested in fucking a woman old enough to be their mother as I am disinterested in fucking a child. Happy mutuality of disinterest.) I enjoy this, but it does not define me.

A woman should have the peaceful assurance of maturity, itself an attractive quality. What I wear, where I eat, the music I listen to, the clothes I wear reflect my preferences, not those of some imagined target audience. I did enough of that in my twenties, thanks! Why should I be scrambling to stay girl-thin, to know and be all things trendy, all in an attempt to stay sexy - a self-denying attempt, if 'sexy' is defined by twenty-somethings, something I manifestly am no more.

Sexy is not defined by taut skin and low-rise jeans and the right music on the MP-3 player.

And sexy is only a small part of who I am, anyway. It's a part that probably gets me the most gratuitous attention, which is nice, but it's the least meaningful. I can get attention for something I've written, for a clever conversation, for an interaction at work, for a piece of music played well, for the warmth of my smile.

Or I can get along just fine without the externals, because internally, I am sound. I know who I am - I don't need others validating my existence by their notice. Though I would hate to be invisible, I doubt I ever will be, because I am, and always have been, more than my sex appeal. Sex appeal may diminish with time. Who I am will only be deepened and enriched with age.

"It is sad to grow old, but nice to ripen." Brigitte Bardot.