Unless you are the sort of person who demands that great parties are thrown in your honour with balloons and streamers, birthdays should be ignored once you have passed the age of 21.
When I reached the age when the candles were beginning to cost as much as the cake I decided that a birthday was not something to be advertised, especially at work. There, one's age should be kept as secret as credit card details at a convention of hackers.
I recently turned 50, however, and this was one landmark I found it impossible to ignore. News somehow leaked out. A cake arrived at my desk in my vast open plan office, and all attempts on my part to divert it discreetly into a side room failed.
I finally had to face the ageing process head on. I am not over the hill yet, but I can see the view on the other side.
I begin to pay attention to the whiskery gents who talk about pensions at union meetings, and, who knows, one of these years I may even ask what an annuity is.
Suddenly, I have found myself living up to certain stereotypes of ageing that I used to observe in parents and grand-parents, and spend as much time looking for glasses as the TV remote.
Now that I am 50, I can remember in meticulous detail what a Latin teacher said to me in an obscure moment in 1973 – and how I was "indolent, insolent and impertinent".
But I can't really remember why I decided to go upstairs 10 seconds ago. Oh yes, I was looking for my glasses.
From my time as a young reporter I remember judges who thought Gazza was an Italian opera, and 'Hot Press' magazine was a journal devoted to airing cupboards.
Now I am 50, I take pride in a certain ignorance of icons of popular culture, and find myself muttering "Who is Bruno Mars?" When someone mentions Angry Birds I think of Mrs Thatcher.
I realise that I am almost old enough to be a judge – I look under the wigs of some of their Lordships and notice they are beginning to look like my contemporaries.
Middle age may have started in earnest, but some of our leading lights offer comfort that there is still a long way down the hill.
When this country was looking over the edge of a cliff into the abyss, who did we turn to but Michael Noonan, now 70.
Youthful exuberance is all very well, now that I am 50 I like to repeat in the comforting mantra, "You can't beat old dog for the hard road".
As Victor Hugo remarked, 40 is the old age of youth and 50 is the youth of old age.
So really, I am starting a second youth, and in 20 years' time I can ponder the question: "So now I am 70 – am I still too young to be a Cardinal?"