"Not that our conversation ever flagged, or that she showed any signs of weariness during our walks; but we had not a sufficient number of ideas in common to make a great stock. We could no longer speak incessantly of our plans, which henceforth were limited to plans of enjoyment. The objects around us inspired me with reflections which were beyond her comprehension. An attachment of twelve years had no longer need of words; we knew each other too well to be able to find anything fresh. The only resource left was gossip, scandal, and feeble jokes. It is in solitude especially that one feels the advantage of living with someone who knows how to think. I had no need of this resource to amuse myself in her society; but she would have needed it, in order to be able always to amuse herself in mine."
January 1, 1970
https://en.wikiquote.org/wiki/Confessions_(Rousseau)