I have zero idea if this is the right place to post this.

I don't understand one thing basically I have my room and for some reason it seems that hearing inside things from outside the room is pretty hard
,but hearing outside things from inside the room is easy

My walls are out of brick but there is a hole that was previously a dor that is filled with cotton and covered with screwed on plywood.
And I simply don't understand how this is possible and if it even is possible.

So my question is if I'm just retarded or if my room is "one way sound proof"