How old would you be if you didn't know how old you are?
I'm confused. And it has nothing to do with my age. Or rather it has everything to do with age. I have three reports in my in-tray, all on the subject of age and, while at first read, they may appear to concur with each other's findings, there is a contradictory element running through them - which is where my confusion comes in.
First off, a report in The Lancet by the Danish Ageing Research Centre says that as a result of rising living standards - for those lucky enough to experience such - there is a 'realistic' likelihood that most westerners born since the Millennium will live to be at least 100.
In particular, the science of bone prosthetics is advancing rapidly, so future generations of old people will be spared aching joints and slow mobility. Throw away your walking stick, check yourself into a bone prosthetics clinic and come out all spruced up and rearin' to go.
Meantime, a survey by German scientists, in the current Social Indicators Research, shows that, for the 1001 people interviewed at least, we humans are at our happiest at 74! Believe it or not, it's downhill till 40, then life gets better and better and is at its best at 74.
Now, assuming those surveyed know nothing about all that bone prosthetics stuff, what could possibly make them believe that your schooldays are not the happiest, that life does not begin at 40, but at a ripe old 74?
Is it possible that we become more appreciative of what we have as we move on through the years?
"Compared to younger individuals, old people tend to place a greater emphasis on emotional aspects of social interactions and are likely to remember the emotional content of their experiences,'' says the research paper.
Well, that's their drift anyway and it does have ring of common sense to it.
So, to the last report, which is the one that really gets my goat.
According to a study, the average person in the UK believes that youth ends at 35 and old age begins at 58. In between - all 23 years - is your middle age.
The news that 58 is 'over the hill' may come as a surprise to those of you who have passed the milestone and feel you are not yet, by any stretch, in the twilight of your life. And such news puts Gordon Brown, and Oscar winner Kathryn Bigelow in their place, with the sultry and sexy Kim Cattrall (left) edging close to that 'dangerous age'. Though not there yet, I'm not far off it, but feel anything but old. In my mind I'm about 10-years-old. And there's still a whole world out there to explore.
And I still have the same wonder about it all as when I was 10.
The finding that society regards people in their 50s as getting doddery, despite the evidence that older people are living more active lives than ever - what an inspiration we have in Bruce Forsyth at 82 - was revealed by academics from the University of Kent.
Prof Dominic Abrams studied data from 40,000 people across Europe, who were asked: when does youth end and old age begin? For the UK, the average response was that you stop being young at 35, and start being old at 58.
But the figures also showed that opinions differed among age groups. Those aged 15 to 24, thought youth ended at just 28 and old age began at 54.
Not surprisingly, people in their 80s were more generous. They regarded the final year of youth as 42, and the onset of old age as 67.
So it seems that what counts as young and old is very much down to the age of the beholder. Or, perhaps more aptly, in the eye of the beholder.
And we men, apparently, regard the end of youth and start of old age as beginning two years earlier than women do.
There were also large differences among European countries. Youth was perceived to end earliest among the Portuguese; they said it was at 29, while in Cyprus it was 45. The Portuguese also thought old age began at 51 - whereas Belgians believed it took at lot longer - 64 in fact.
The population of the UK is ageing. Sixteen percent are 65 or older, and for the first time that age group outnumbers people under 18.
I suppose, at the end of the day some people 'get old before their time', while others 'just never grow up'.
But ultimately, short of those futuristic bone prosthetics, growing old is a process over which we have no control. It's either migrate to Cyprus or find consolation in the words of Dr Carlo Strenger of Israel's Tel Aviv University who says: "If you make fruitful use of what you have discovered about yourself in the first half of your life, the second half can be most fulfilling.''
It's called 'wisdom', I believe, and, if you're lucky enough to find it, is the best thing that comes with the inevitability of getting on.