synopsis of actuality:

"You are old, Father William" his friends did remark,
"And doing quite well, in the main.
But we still remember when you stood on your head-
Why don't you do it again?"

"In my youth, it was easy", the old man replied,
"But my CAT scan was an interesting sight"
The doc said:," Your vertebrae's seen better days,
"And I recommend staying upright!"

(I used to celebrate birthdays by standing on my head...until 55 or so)