As I have stated before, I see things a little differently than most people. People I have told this to have called me crazy, and they're right. I AM crazy. However, not everything that I can see is "abnormal." I notice things about the people I see.
I was talking with a close friend of mine not so long ago about a train ride we went on that day. I Told her some of the things I remembered about the people on the train and she said I was creepy for looking at other people in public, much less remember things like what tattoos they had visible, the color of their clothing, even that their phone had an ugly fake gem decal in the back.
I hear a lot of people say they like people watching. The same kind I people who say they want to watch a movie and then open up tumblr on their phone halfway through the opening scenes.
Why bother if you're not going to pay attention?
On just about any given day I go out, I could tell you how many people were barefoot, how many guys had fake gems on things they owned, peoples tattoos, the colors of said tattoos, how many people needed an attitude adjustment, how many women had purses, etc.
I mean, don't get me wrong, it's creepy to stare at people you don't know, but I can get most of that information with just a few glances. All I do is pay attention.