You know what they all have in common? You ride in a compartment which makes frequent stops at which some people board and others exit. You would think that most people would instinctively understand that the logical, most efficient way for this to work would be for the people waiting to get on to stand back and let the people wishing to get off do so before getting on. But you would think wrong. It just amazes me how selfishly many, if not most, passengers behave. The people in the car get up and stand in the doorways, blocking traffic both in and out, three or four stops ahead of time. When the train pulls into a station, the crowd waiting to get on barges in as the crowd waiting to get off barges out. The ones getting on step through the doorway and stop, oblivious to the crowd behind still waiting to board. No one respects the elderly or families with small children trying to stick together, while some parents of small children hold up everything manhandling refrigerator-sized strollers through the doors and down the aisles. This one happens at the store too: it never occurs to some folks to get their money or fare card or checkbook out until they are actually at the register/turnstile/whatever. Often they are engaged in a cell-phone conversation the whole time, and prop the phone between shoulder and mouth to keep yakking away while fumbling around in their purse. Speaking of which, there are the cell phone yakkers who carry on conversations at the decibel level of a 747 on its takeoff roll without a pause for hours on end. I'm sure these people must have to have the phone surgically removed from their face every so often. There are several sub-species of cell phone yakkers. Those who want to impress everyone with how smart/important they are by ostentatiously conducting their business using a great deal of business or techie jargon. Gossipers. Domestic disputers continuing long-running fights with spouses/significant others/children/parents/friends/associates. Complainers airing their side of long-running disputes with spouses/significant others/children/parents/friends/associates to third parties. Serial disputer/complainers - instead of one long-running fight, they engage in numerous short fights in succession, calling others in between to complain about the latest antagonist. Planners who set up all the details of social events from what's for dinner to who to invite while in transit. The infirm, who must relate their health problems in minute and graphic detail. Then there are the seat hogs. They may pile their coat, laptop, purse, briefcase, etc. on the seat next to them, or they may sit on the aisle, blocking the window seat, or they may lie down across both or stretch out their legs into the other seat, or some combination, more or less daring anyone to claim the other seat. These strategies are sometimes supplemented by sleeping (or pretending to sleep) or by neglecting personal hygiene. And you know most of the people described above are completely clueless at how rude they are. It just doesn't even occur to them to think about other people.