Korean footwear rules are confusing

Before I came to Korea I put a lot of thought into what shoes I would pack.  I had limited room in my luggage and yet thought that I would need multiple kinds of footwear for different aspects of life.  Casual, workwear, etc.  I was wrong about this.  Because Koreans have very special footwear rules.

When entering a building or a room or someone's house, you almost always have to remove your shoes.  Especially if the floor is a little bit raised from the main entryway.  This is common in restaurants, the gym locker room, at saunas, and in some bathrooms.  In these places you remove your shoes and then just walk around in your socks.  For this reason, I plan to carry socks with me in the summertime because bare feet indoors outside of my own home is a little weird to me.

At school we also remove our shoes when we enter the building but instead of walking around in socks we wear "slippers".  Slippers are not what you would think of as bedroom slippers, all soft and cozy and warm.  They are instead what I think of as flip flop shower shoes.  Plastic, cheap, and easily disposable.  Students all have very cheap slippers and I'm sure they go through many pairs throughout the year.  The local cheap general store sells them for less than $5.  Teachers (including me) have slightly nicer pairs that are a bit more comfortable and last a little longer.

This is basically what slippers look like.  You can forget about coordinating your shoes with your cute work outfit.

All of this is fine and not confusing at all to me.  Korean people don't wear the shoes they wear on the street indoors in order to prevent carrying filth inside.  Makes sense.  But what doesn't make sense is that no Korean person follows this in school.

Seriously.  I have seen almost every single Korean person at Danyang High School wear their slippers outdoors.  They do this.  Going across the street to get hot chocolate?  Wear your slippers.  Going across the dirt soccer field to the auditorium?  Wear your slippers.  Going in a car to a restaurant and back?  Wear your slippers?  Going outside for a snowball fight?  Wear your slippers.  Both students and teachers do this.

More than once when I have stopped to change into my shoes before leaving for somewhere a teacher has stopped me and asked what I am doing.  When I explain that I think we're supposed to change our shoes they say "Oh no, we don't have to."  When I ask why I am given a multitude of reasons often including something like "We're just going a short ways." or "We're teachers so we don't have to."  But whatever the logic, I still try to follow the rules as best I can.  Because I don't want the indoors to be dirty either.