When Smiley Me Not Smilling

A gentleman had known me for about an hour. When he was in a conversation with another person, I didn't manage to acknowledge his presence, I didn't recognized him even by a smile at a time. Discreetly, this gentleman came across to tell me, that I was very arrogant and this reflected my bad manners. I knew that I had already created him a very unpleasant impression of myself. At the same time, I believed that I was not being rude to him, and never to anybody at all. I think so; in fact, I am quite sure. He just disagreed with the way how I carried myself.
This could only be a minor misunderstanding, thus. I didn't talk much. I found it frustrating that I couldn't make myself clear to a person who doesn't know me well. And I was rather displeased as I was told in the way that I didn't know my basic manners. It seemed that I was immature enough to know myself better, and I was dejected to learn that this person didn't treat me as an adult. In a second, I took a mournful view of human affairs. I didn't feel like getting to the heart of the problem. Hope against hope, I could have a better tomorrow.