Do I look friendly?

I suppose I must. People keep striking up conversation with me when I least expect it. Like when I'm sitting alone in a study cafe with my headphones in. I never really expect people to try to talk to me in the first place but I guess I look approachable. I mean judge for yourself:

 But so here I am just typing away. In basically the exact same spot I was last night. And at the table next to me is the same (cute) gray coat that was here last night. I remember it because there was no owner with it last night and I thought about snatching it but let it be. I figured someone would come back for it. But alas here it was. So a guy sitting at a table on the other side of the jacket was there with his buddy. Side note: the buddy is in my exercise class and we both had the glimmer of recognition and agreement on mutual ignoring of each other. Anyways the guy asks me if it is my coat. And as you can see in the picture, I am clearly wearing a coat. So I say no and he moves it. I say how it has been here since last night and how I was surprised no one had come to claim it. Who leaves without a coat? But I'm considering leaving with an extra one since it is still here. Is that really awful? The guy leaves the cafe area a few times and then randomly comes back and asks me a question. I have my earbuds in so I take them out but still don't understand when he repeats the question. Finally I get it. Do I like jazz? And I do. I listen to jazz all the time when I am studying or doing homework. Apparently there is a jazz concert going on upstairs that he simply must enlighten me on. He even has a pamphlet. But he has to finish his work real fast so he can go watch. I just sort of nod and go back to my lab report. But 10 minutes later when he leaves to go upstairs to listen to jazz, he gives me a wave and says goodbye. Okay perfect stranger. I gave a wave back to be polite.

I don't understand how this happens to me whenever I am in the library. Someone is always talking to me and asking questions. People I have never met before and likely will never see again. I guess I look like a nice person. Little do they know...