When you have a regular commute you usually end up seeing the same people, day to day, week to week. Even though you will probably never speak or know anything more about them than their commuting habits, these people can become, Travel Buddies, of sorts.
You may wonder from time to time; should I say hi? Could we be best friends? But you probably never do, so you'll never find out if your silent, stranger of a travel buddy is in fact your best friend.
This is why we have mp3 players, and, if you're a little old school, books. So we don't sit on the train, bored, while awkwardly trying not to stare at your travel buddies. And if you do get stuck without a distraction or a reason not to notice your fellow commuters and then simultaneously 'not look' at each other. You may accidentally let out a hello.
This can be okay and you may be able to recover your oblivious co-existence.
You accidentally, half intentionally, become confident that you may enjoy a conversation with a 'Travel Buddy'.
I'm not saying this will definitely be a complete and utter disaster, akin to stepping on doggydoo and then slipping and falling onto your behind. But, it probably will be.
Usually one of two things will happen. Either the other person responds, and they turn out to be an annoying douche. That for some reason, thinks your best friends. So you try to convince them that you need to make an important phone call to get out of the conversation.
That person awkwardly tries to make themselves believe they didn't notice you by pulling out their phone and making an important call. And thats when you realize...YOU, are the annoying douche that everybody else is trying to avoid by bringing an mp3 player or a book on the train.