Everyone asked a 100-year-old man for his health secrets:
The old man said:
I’ll tell you a secret. I’ve been married for 75 years. Promised my wife when we got married that when two people quarrel, the loser has to walk for 5 kilometers.
I’ve been walking 5 kilometers every day for 75 years !
Everyone asked again: But how come your wife’s very healthy as well?
The old man answered: I’lI tell you another secret. She’d been following me to make sure I really finish the 5 kilometers!