What's their story?

I was at the mall today trying to finish my last minute shopping. Of course I am not done and have managed to go Christmas shopping at least 8 times. So, for all of you, you are just going to have to deal with things not getting there by Christmas. Anyhoo, on my excursions to the mall or any public place for that matter I people watch. I love to people watch. And although my attention is usually caught by people making out, boys who are 11 and have an 11 year old girlfriend, girls wearing UGGS in hot ass weather, and etc., my attention never stays on them. Usually, I end up focusing on the people who appear to be lonely to me. And I always wonder, what's their story? Because I always feel bad for them. And it's not that they are going out of their way to appear lonely. For instance, today I noticed a tall skinny teenager hunched over just wandering around in Pacsun with a sad look on her face. She was alone and seemed kind of lost. I mean I know she wasn't lost. And then I watched the sales person be an asshole to her and at that point I wanted to say something, but I didn't. Now, having seen her is really not going to make a difference in my life one way or another but it made me wonder if I look sad or lonely even when I am not. And if i am lonely, can others tell?