A curious stranger. Or was it strange curiosity?

The other night I was sitting on the light rail after work on my way back to my dorm. I was stressed out and a little upset, but I tried to busy myself in my book. I noticed two young men, maybe early to mid twenties, get on the light rail. One in particular noticed me. I caught him looking at me a couple times, and again attempted to busy myself in my book. It was dark outside, and there were lights on inside the light rail, making the reflection in the window as clear as if it was that of a mirror. I pretended to look at the scenery, but instead I watched the young man looking at me in the reflection. He wasn't creepy looking or weird, and had no evidence of being homeless or crazy. But every time I looked up from the book, he was looking at me. I just tried to ignore him. After about half of the 40 minute trip had passed, he got up. There was no way he was going to come sit by me, that would be too much, even if he had been crazy. I was wrong; he sat down in the seat behind me. "Hey," he said as he leaned forward towards my seat. I still had my nose in my book, trying to ignore his obvious presence. Curiosity overcame me. I turned to him as I tried to pull off the oh-I'm-sorry-I-was-engrossed-in-my-book-and-didn't-hear-you look combined with the were-you-talking-to-me look. I'm not sure if it worked, but he began talking. He apologized repeatedly as he explained that he had never approached a complete stranger with such odd intentions. He went on to explain that he was intrigued by the expression on my face, that I had a "perplexed, fixed" expression. (I had not even been aware I had an expression on my face.) He explained that the emotion in my face was so intense and so real, he felt "engaged," to the point where he would walk up to a complete stranger and risk looking crazy, to get a better understanding. He said in some strange way, he was giving me a compliment-- he could see how much I cared, he could physically see love in my expression. He even used those words. It was so odd, but it was so nice to hear. I'm always so afraid the people I care about, even people who aren't necessarily a huge part of my life, don't realize that when I mess up or when I'm being difficult, I feel it. My actions aren't things I brush off easily. I always feel like I exert so much energy and become so exhausted stressing over the problems I create with people, and I find it so interesting that a complete stranger, someone I had never even had the opportunity to affect, could see it just by looking at my face. It was just such a strange experience.