C has a sense of humor. A pretty good one, in fact. Most of his jokes involve some form of word play.
For example, the other day he said he wanted to go down the apple stairway, and up the banana stairway. It took me a moment to realize he was talking about the A and B stairwells in our building. He thought it was quite funny.
Another: when asked if he wanted some Play-Doh, he replied, "No, I want Work-Doh!" Giggles and more laughter.
If he makes us laugh, he is overjoyed and will say the joke over and over. And perhaps this is the most critical point: C's desire to tell us jokes is a way for him to connect on a deeper level, to share his thoughts, and to take pleasure in his ability to give us joy.
A therapist once told me that C's sense of humor was somewhat unusual, and might be considered cause for hope. Sounds good to me.