Asked what she had learned from 47 years of marriage, a close acquaintance of mine said:
"Never assume someone is dead just because they're unresponsive."
Which inspired me to a bit of would-be wit:
"Say what you want about marriage, it's still the best known cure for unnecessary conversation."
And reminded me of words once overheard:
"My husband is a man of few words, and by the time we got married, he had already said them."