I recall from childhood my grandfather saying his back hurt because he was kicked by a mule when he was 15. He said things you thought you got over when young come back to haunt you when you get old.

Then in my thirties I was having lunch with a gentleman in his fifties and I was commenting how I had slowed down from when I was 19 or 20. He told me that every decade comes with new bodily decline.

I recently had the VA grant me a 10% disability rating for a parachute mishap that happened when I was 18. It's usually not too bad if I wear a brace, but now all of me aches from a couple hours of yard work whereas in my 30s I could hike a local trail 10 miles and then come home and mow the lawn for 3 hours.

At least I'm still immature!