I find this age thing quite disorientating. My elder son will be fifty next year but doesn't seem that old. When I was fifty, his late mother was diagnosed with breast cancer. The President of France is still in his thirties and his wife is in her sixties.
In old age, one sees life retrospectively as if through a lens backwards; time is compressed. My thirty-seven years in the Navy seem to have the same storage space in my brain as six years at Coatbridge HIgh School. Thirty-eight years of married bliss seems like a brilliant one-night-stand - not that I would know anything about that. A twenty-five year old lad now seems like a teenager yet I was charge engineer of a submarine at that age.
The good news is that, as President Macron has so ably demonstrated, a sixty-year-old woman seems like a twenty-something chick but with much greater depth. I have now reached the age when I can fancy a great-grandmother.
So, why the hell do people regard their fortieth birthday as a doomsday; it's only half-time. You may go to extra time and penalties.