I am now 67 and am having the time of my life. Inevitably, the way I am feeling and acting now is the product of both my age and my recent retirement, and the exact contribution of the two components is difficult to disentangle. I actually retired from being an academic with an active role in the medical establishment two years ago, and to minimise the “shock” of retirement I had started my withdrawal several years earlier. So, by around the age of 63 years, I had cut my weekly “hours” from about 75 to 40, a reduction achieved by stopping being editor of the Drug and Therapeutics Bulletin; no longer being a member of the UK Medicines Commission; no longer  chairing various committees at St George’s, and by halving my already small clinical (outpatient) practice. These changes left a sizeable dent in my influence and responsibility, but at the same time gave me a wonderful feeling of space and autonomy.

As well as making these material changes, over those last few years I devoted a lot of mental energy pondering what it was that made some older people part of society and left others marginalised or invisible? Why it was that some older people appealed to students, young adults and the media while others were dismissed as “old and grey?”  What it was that gave some older people immediacy and relevance? For me, the conundrum was ultimately resolved through exploring the qualities of Bertrand Russell and Nelson Mandela, two of my heroes. I realised that despite their ages both felt passionately that societal changes were needed, both campaigned to bring about these changes, and to this end neither stopped challenging – governments, authority, the establishment,  traditions, dogma, youth, and of course themselves. For neither of them was there a place for complacency. Seeing Russell in his late eighties sitting on cold paving stones in Trafalgar Square campaigning for nuclear disarmament has been an enduring inspiration. So, with change and challenge as my bywords for older age, I felt fortified not least because these were ideals with which I personally identified.

I became officially older in May 2007 when, over about ten days, my salary ceased, I started receiving my pension, I got my “golden handshake,” and I was honoured with a wonderful leaving do (symposium, party and dinner) with all the “goodbyes”, warmth and well-wishing one could ask for. “Closure” allowed the older me to begin my new life.

There is no question that there have been major changes in the way I now live and think, and how I see myself and how others see me. A key immediate change was in life’s momentum. What a relief and pleasure it has been to have space to think and to ponder, and to escape the frenetic demands of the workplace. Coupled with this there is now a freedom to make decisions where priority can be given to my interests rather than to those of others. Notwithstanding these changes, I find myself frailer (sprains and strains take longer to resolve), my hearing is deteriorating (so I tend to shout), I stoop more and need stronger glasses. At the same time I more often go to exhibitions, spend longer on trips away from home (France, USA, Cuba next!), spend more time browsing the internet and watching TV (mainly rugby and football), more avidly read obituaries (friends and those who have died younger than me get particular scrutiny), and seem to be going to more funerals (better than the alternative).

Paradoxically my trips to the gym (daily – almost) have meant that my overall fitness levels have improved (33.5 minutes to do 400 calories on the exercise bike rather than the 44 minutes at retirement).

I am still passionate about causes, (I don’t think I have mellowed much) and obviously still challenge. It is in this spirit that my requests for discounts on the grounds of my old age are made clearly, proudly and loudly. I still teach (around one morning each week, and both sides seem to benefit), occasionally I act as a consultant and lecturer (although both make me feel uneasy) and comment in the media (it still gives me a kick to be asked), and I still write (see this). But my greatest pleasure and stimulation comes from learning French. At the moment I have 3 lessons a week (so 4.5 hours) and probably spend around 15 additional hours doing ‘homework’. In the last 4 years I have gone from “elementaire” to “superieur” and find myself able to learn facts faster than I ever did. I often think how much easier school and university would have been if I had the mind I have now. In doing my French I have also discovered how much I have always loved learning and how for me it is important to get “inside” a subject and understand its intricacies (at the moment I cannot get enough of grammar!). Oddly, and, just like in my “working” years, I still feel there are not enough hours in the week

Being older is fun, continually challenging, and part of a fascinating experiment. I am content in my new self, and am surprised to be discovering bits of me of which I was unaware. I would advise anyone to give older age a real try.

Joe Collier is emeritus professor of medicines policy at St George’s, University of London

Also by Joe:
On being an atheist
On being male