I found out from his new owners that Irina, one of their ewes, had been befriending him. He would be happy with her around and get bummed out again when she went away. Good Lord, I felt every step of that process! Finally, I felt him go away, and told him to go be happy, live his life, and know that he is loved here, so none of us at DewGreen are lost to him.
I don't know if he got the message, but I would like to think he did. And after that, I have not felt Truffle around again. At my last communication with his new owner, he had settled in nicely and was ready to breed his ewes.