On the Arizona Trail, the one place where you cannot truly wild-camp is inside Grand Canyon. You have to use designated campsites there, and there are lots of people (unfortunately). While looking for some seclusion (and trying to find birds), a man appeared and started talking to me. I found his behaviour strange and I had an uneasy feeling about him, but he was friendly and I really didn't have any way to escape his company because I was camping among twenty or so other small tents. So we ended up on a beautiful beach along the Colorado River at the bottom of the canyon. He had cans of sardines which he generously shared with me (delicious - though a terrible idea, because you have to carry out the smelly empty cans in the boiling heat).
Then he started telling me about his life. He told me he was a former inmate. He claimed to be innocent, but was framed by people. He claimed to have been tortured into confession by the police. As he was now a registered criminal, he couldn't get a house anywhere so he now lived in his (passenger) car. As he was telling me all this, I could see he suffered a lot psychologically, but my gut also told me wasn't completely sane, potentially schizophrenic and delusional. I wasn't sure what to believe. I kept feeling uneasy about him. Not because of his criminal past but the way he interacted with people and some (imagined?) things that he told me, which could perhaps lead to unpredictable behaviour. He talked for a few hours and all I did was listen and try to understand what he was telling me. When it was time to go to my tent, he thanked me for having listened and not judged him.
The next morning I packed my tent and left early and was relieved that I haven't run into him since. But in hindsight it was an interesting experience.