This is autobiographical.
I was cheered up by a story in today's newspapers: a large scale psychological study led by Archana Singh Manoux has shown that cognitive abilities (reasoning, memory - I forget the third one) start to decline from around the age of 45 not 60 (as previously thought).
When I took early retirement from my University teaching post at the age of 50 (though continuing to teach part-time for another three years)I had this feeling that I was past my best and that it was a good idea to quit while it didn't show. After all, I thought, footballers don't go on forever so why should academics? I had other reasons for quitting, but this line of thinking was at the back of my mind.
I was aware that my memory was nothing like as good as that I possessed in my teens and twenties.I no longer had the kind of visual memory which allowed me to call up diagrams in the Economics textbooks I studied at "A" level and University. Nor could I any longer be sure that a quotation I was looking for was on the right or left hand page of a book.
For years, I had got away with very sloppy note taking because I could always remember enough of a book to go back and simply look again. And supervising students, there was a time when I would dictate reading lists rather than print them off in advance, complete with publisher and date of publication.
Of course, I had a huge back catalogue of knowledge and intellectual strategies, but I found learning new things increasingly hard. When I started a Russian course at the age of 53, I soon gave up. I wasn't quick enough for my own liking.
True, I did manage to switch from being a reasonably successful academic (go to www.selectedworks.co.uk) to being a reasonably successful specialist stamp dealer (go to www.armeniazemstvo.com). But in truth, I can no longer remember stamp catalogue values in the way I could remember them as a boy (when I could also tell you the results of football matches played by Dartford FC and such like). This is a definite handicap when it comes to making quick decisions on whether to buy.
One of the things I like about my Blog is that it does not require me to hold in my head a mass of information over a long period. When I worked on my doctorate, I held it in my head over a period of at least seven years, more if you count the time then spent converting part of it to a book (Language in Mind and Language in Society, Oxford University Press 1987). I don't think I could do that again and I am not at all sure that I would want to: it was exhausting first time round.