Oddly enough, the OP is one of my pet peeves. I get extremely annoyed when people try to push their way through me to get through the door I opened and am currently going through.
I have “experimented” extensively with people and doors. I do it nearly every chance I get, and they never fail to amaze me. Buildings with 4-5 sets of doors are my favorite. I see people walking in a path to intercept me and my door, so I switch doors, usually the furthest from them. They follow me, instead of opening their own door, they expend more energy so that they don’t have to open it themselves.
I have also walked up to a door and stoped to do something like tie my shoe in front of my door, and the person on the other side (with a door to themselves that I am not blocking in any way), will wait for me to finish instead of opening his/her door.
Sometimes up to 30 seconds.