I had friends at UCSB, and when I visited I would make time to take John away from St. Vincent's for an afternoon. It was interesting to see how he interacted with strangers we met on a trail, in a convenience store, or really anywhere. People didn't shy away. Some were perplexed and looked to me for guidance, but John was so open and pleased to meet them that their attention snapped back to him. His diction and pronunciation were better back then, and unless he was talking about Godzilla or Frankenstein he was usually able to converse a little bit. The bottom line is, it's very difficult to not respond positively to someone gives you this look, extends their hand, and says, "Hi!"
John wasn't oppositional. He got along with everyone pretty well. But if the opportunity arose to harmlessly misdirect someone, he might do it. He'd also make knowingly silly threats, like picking up my camera bag and saying, "Bye, Joe. I'm going to Hawaii!" Why Hawaii? We don't know. But we know that he knew it was a comically empty threat.
John was a huge fan of the actor Ray Milland, and would do impressions of him at the drop of a hat.