New year is a time to wonder what it all means. Can it really be 2013 already?
Why are the policemen getting younger? Same with Presidents and Prime Ministers. It occurred to me that from now on, I'd probably be older than most of them.
Cameron and Blair both took office aged 44, younger than any other Prime Ministers since the war. (You can see my chart much better if you click it.)
For all of us, there'll come a day when someone takes office who is younger than you.
In my case, it was Obama, followed by Cameron. Until I looked at the dates, I'd imagined I came somewhere between Blair and Brown. I now discover Blair is four years older than me and Brown six. Is it common for the middle-aged to assume that leaders are younger than they actually are?
I'd noticed the opposite effect in how I thought about my children's teachers: I've always found it hard to believe that even the most fresh-faced of them could possibly be younger than me. It must be something to do with the authority of a teacher.
But with politicians, it seems to go the other way. If you've grown up with Heath, Wilson and Thatcher as 'your first' Prime Ministers, you can't help thinking of upstarts like Blair and Cameron as lightweights, which perhaps leads to the idea that they're younger than they really are.
So here's a handy chart to show when you crossed or will cross the line that makes you older than the Prime Minister or the President of the United States.
Of course, you can cross the line and later find yourself below it again if, as quite often happens, a new leader is older than the one before - as when Johnson followed Kennedy, Reagan followed Carter, or Callaghan followed Wilson. If you have just crossed the line, you'd be given a few bonus years on the right side of the line again - but it won't last.
(The chart looks terrible below, but just click to see a nice clear version):
It turns out that the average age of Prime Ministers since the war has been 57, and the average age of Presidents has been 60 (although their average ages of coming to office would be younger).
So I have extended the politicians' lines into the future at those ages, so you can get an idea of when you're going to be feeling old - if you aren't already.
If you would like to check your first younger PM or President of the USA, there's a spreadsheet here (for anyone born since 1940).