Enplaning and deplaning is a fascinating example of how human beings interact. It seems like many passengers boarding a flight want to get on the plane as soon as possible. Whatever their specific reasons, this tendency has probably been exacerbated by baggage fees that have increased the amount of baggage brought on board and the high demand for the very limited amount of space for said baggage.
So everyone jockeys to get on the plane first, dragging countless bags, purses, and strollers. In my experience flying and boarding early, I have never made it down the jetway without having to wait in line. Strollers are left at the door, to be taken down and placed in the belly of the plane. Often times, a bag or two that just won’t fit gets bumped as well.