As wines mature and oak in the barrel, and take on tones and subtleties and shades over the years, so it is the same in the slow evolution of a friendship. Neither are static. Gradual, imperceptible change is taking place in the depths pushed on quietly by almost submarine like waves.

I notice now that it's less frantic, passionate intimacy (when you're in daily contact) to more understanding and accommodation as the years sweep by in recognition of something else, that great, but welcome, intruder - life.

I've been thinking about this since last weekend when I met an old friend whilst I was in New York. We've known each other for over twenty years. Initially we were a couple, although if I'm realistic, it was more a light romance, a summer romance in many ways; distance did for us ultimately - we were an early NYLON couple and a young one at that, scarcely in our twenties. It fluttered to an end softly and I hope painlessly; but it did n't exhale a final breath and expire, no, it reformed into another state of closeness - friendship.

We've kept this afloat for two decades through letters, faxes, phone-calls, endless e-mails,visits to London where I live and New York where she is.

I am very fond of her; she is, and this is something I once alluded to in a blog entry years ago, one of those people who have touched my life and transformed it.

But do I really know her? Does anyone really know their long-term friends once life has stepped in between you and led each of you in different directions and into separate adventures? Evolutions occur that in no way can you be privy to or even aware of. Take my friend, I've only ever known her as a woman, that was how she was to me, and remains like that if I'm honest; but today that's only one aspect, there's more that life has added: she is a wife and a mother now. I still remember her as a woman. That sense is crystallised almost but now she is more, something richer, deeper, more vital, much more complex.

I've been fascinated by this realisation for days. It has only added to my gratitude for knowing her. There's more to find out. Just like prisms turned in the light - always something new and unexpected appearing.