Come On We're In A Corridor and Actually That's A Door

In high school I noticed that people did horribly strange and annoying things while we were all milling about toing and froing between lessons, I put this down to age and thought I'd be safer when I got to College. Oh how wrong I was.
Okay so I'll admit it's not half as bad a problem as it was in high school, I have as of yet to see anyone stop on the stairs and tie their shoelace whilst everyone tries in vain to get up and down the stairs around them but there are still some pedestrian issues.
I can't count the number of times I've walked into someone who has stopped in the middle of a doorway and who has then looked at me like I've shot them. I just don't understand it, the door is made for people to walk through not for people to stand in aimlessly so why do I find myself being stuck behind people who think that doorways were meant for having a bit of a rest? I am trying to use the door for it's intended purpose, to get from one room to the other but some people haven't quite grasped that's what you do. Maybe we need some door etiquette classes or a "how to use doors for dummies"-esque book.
A similar issue occurs in the corridors. Now there are roughly around 2000 students in college and the corridors are incredibly narrow considering that number yet people still have no spacial awareness. Many a time, most notably on my way to Geography, I've had to move people aside just to try and make my way down the corridor and they still choose to stop and have a natter with their pals in the middle of a narrow and congested corridor. Why? No-one may ever know but it certainly makes absolutely no sense to me as I try to make my way through the throngs of people and those who stop like a rock in the river to try reach my classroom which is at the very end of said corridor. Even the staff have to fight their way to their rooms.
So these people have at least 5 GCSEs and are studying at a higher level but still haven't quite worked out what to do in a corridor and what the function of a door is. Help us all.

All The Best,

A Grumpy Old Teen