I was studying the other day, and some guy came and sat at my table. He said he needed to use the outlet for his computer that was near my table, but then he started asking me questions, like about what I'm studying and why. And sometime through the conversation, he mentioned he's studying abnormal psychology. He was really friendly, and it amazed me how natural he was with talking.
then he stayed there working on his computer for at least an hour, while I plowed through my math work, and it seemed like he wasn't really working on anything, because he would get up a lot and would chuckle at things he read on his computer, and I felt sometimes like he was watching me for about a few straight seconds, or glancing up at me a lot. I quickly began to wonder whether he had some other reason for sitting at my table, for example, maybe to observe me, if I look like I might be pscyhologically abnormal. And some other grad student came by and asked him why he was sitting out at this table, which is another indication to me that he didn't really need to use the outlet there. And when he left, he didn't say farewell or any sort of parting greeting, which I think would be proper after people had a short conversation spontaneously.
Was this just a friendly guy, or do you think he may have been analyzing me if I look abnormal (which, I think I probably do)?