Decades ago, when I was in my early twenties, I remember going to a nightclub with some colleagues from work.

One of the party had to go home earlier than the rest of us, and I remember some of the lads mocking her and saying something along the lines of ‘Well what can you expect, she’s in her forties’.

Despite her being attractive and lively, they saw her as old and past it. But at least they registered her presence, because once women reach a certain age, we seem to escape the male radar.

There’s even been research into the phenomena, which arrived at the conclusion that 46 is the age at which women start to feel invisible to men. It’s the point at which a woman’s confidence falls and she begins to feel uncomfortable with the image she sees in the mirror. A few grey hairs and less attention from the opposite sex adds to the feeling of being ‘past it.’ I know that feeling. It has been many years since young male colleagues consulted me on the best pubs and clubs to go to, or chatted to me about current music or films. They simply don’t see me as ‘one of them’ – and I’m not. Young people see anyone over 30 as old. Forty is ancient, and 50 totally decrepit.

When I very occasionally chat to 20-something men – at my instigation, never theirs – they’re more likely to ask me about the Festival of Britain than Glastonbury, and how much I get in cold weather payments. But then I’m probably older than their parents, so why should they do otherwise?

And I’m certainly invisible to my husband. ‘Oh, hello, when did you get back?’ he will say after work. ‘Two hours ago,’ I’ll reply, having walked past him a dozen times.

It is a sad fact that once you reach a certain age, however young, vibrant and vital you feel inside, you’re not that person and never will be again. Women at 46 also feel their views and opinions are no longer valid. I don’t think that’s entirely true – someone rung me only the other day to ask whether I preferred washing powder or capsules.

The good news is that this depressing dip does not last forever and most women regain their self-confidence by the time they turn 60. I don’t think it’s a confidence thing – more a case of having got used to being invisible, being too old to care, and quite enjoying it.

Only another 10 years to go, then, until I feel good about myself. I might celebrate with a foam party in Ibiza.