Why? I'm just not friendly. I don't enjoy talking. It's filled with social anxiety and if I want to stop talking I can't just stop. I can't just say "you know what I don't want to talk anymore" and then look away in the middle of a conversation. I don't want to spend 20 minutes or half the day wondering how I came across in the conversation. I definitely don't want my time dictated by others. I had a friend actually get mad at me when I said I would ignore someone who struck a conversation with me on BART, he felt I was obligated to respond to not make that person feel shitty, but maybe that person should just have noticed that my body language is all about being left the fuck alone.