I was waiting for radiotherapy once, in a crowded waiting area, & I was crocheting because wait times could be very long. A man opposite me stopped talking to someone & started loooking at me. I had a general impression that he was a bit of a bore & didn't make eye contact because I didn't want to talk to him. He kept very obvously wanting to talk, & finally he asked me something about my crochet which I had to respond to out of politeness.
Once he'd got me to say something, however, he dropped any pretence at an interest in anything other than himself & started telling me things from his life; & though I can't remember what they were, each one was something unpleasant & the combination of these events being recounted and something about the man himself was so 'off' that I got a feeling of intense literal darkness & evil - something I wanted to get away from. I was so glad when they called me in for radiotherapy & I was so unnerved by it that I told the rads person that someone had insisted on telling me his life story. That was all I felt I could say about it, & she misunderstood & said, "Well, some people are lonely," & I said, "But it was all horrible."
When I came out, I got my confirmation that it wasn't just me. He'd moved across the waiting room to talk to another woman (she was on a trolley & couldn't get away from him), & the look on her face told me that she was reacting to him exactly as I had, & she would've done anything to get away from him.
There are people who come onto threads like this & say, 'Evil doesn't exist & that's that.' But of course evil deeds exist, evil behaviour which causes harm to others. If I had to conjecture, I'd say this man had done those things in his life & his mind was filled with those things. It emanated off him in waves. It poured out of him. It's the bizarrest thing I've ever encountered.