I'm put in mind of a favourite verse:

"You are old," said the youth, "and your jaws are too weak For anything tougher than suet; Yet you finished the goose, with the bones and the beak -- Pray, how did you manage to do it?"

"In my youth," said his father, "I took to the law, And argued each case with my wife; And the muscular strength, which it gave to my jaw, Has lasted the rest of my life."