A friend wrote to my wife:
I find it hard to believe that it is nine months since I received your email, and that I failed to respond. I just don't know how the time can go so fast! The passage of time is on all our minds, and I sometimes focus on the difficulty of conceptualising this elusive idea. I wish John - philosophers can do this sort of thing! - could come up with a theory as to why time goes so much faster the older one gets!
To which I answered:
1) When you were six, you had lived for only two thousand one hundred and ninety days;
so each day was more than one two thousandth of your life,
while when you are ninety you will have lived for thirty two thousand eight hundred and fifty six days
so each day is less than one thirty two thousandth of you life,
When you were six, each day > 1/2,000
When you are ninety each day < 1/32,000
so ratio = 2/32= 1/16.
2) When you were six, every experience was new, and was lived through to the full.
while when you are ninety you will have established many routines, which will be lived through mechanically, without being much attended to, and so without registering as an experience with much content.