A lot depends on how your life’s going, of course. But physically, a lot also depends on genetics, and that took me by surprise. Health, energy, hormones etc - I discovered we all age very differently, and the only clue is how long your grandparents lived and how your older relatives are doing.
I’d never bothered about my health or bodycare things like sunscreen etc, and I’d always been a bit reckless. The 40s were when my body started paying all my debts. Old injuries started hurting again. I was slowing down and got tired easily. I had lots of health problems. Couldn’t shake off colds or other infections so quickly. I got skin cancer (cured, thanks to quick NHS action). I noticed that few of my relatives had lived past their 70s, so genetics wasn’t on my side.
All the health stuff got me down. It was a bad time. But it had some good results because it shook me up and made me re-evaluate my way of life. I stopped wasting so much time on things (and in some cases, people) I didn’t really care about. I took up exercise, which has made a major difference in terms of strength, energy and general health.
Out of all the things we have control of, I’d say taking up exercise has been one of the most important for me. I’m still not a fitness fanatic, but I’ve been forced to start taking care of my body because even the NHS can’t give you a new one.