In order for everyone to manage their commute with sanity, there are unspoken rules on the subway. Call them etiquette or common sense, they're the simple actions that make the world run smoothly.
1. If you must wear a huge hulking back pack, take it off and hold onto it in your hands. Even Muppets know this, why can't many strap-hangers?
As I am now old and cranky, this is something that really disturbs me and burns me up. When I see a handsome man with a large guitar case walking down the street, where I once would have thought “He's cute”, I now think, “God, I hope he doesn't get on my train”.
2. Your Daffy's bag does not need its own seat.