People
The thing with trying to be non-confrontational is people do not know you are trying to be non-confrontational, they just assume you do not know better or are simply a pussy and they try to walk over you. Its when people try to take advantage of you most; they forget to do what you tell them to do, they forget to do things you expect them to do, in fact, they do things that are actively harmful except you tell them explicitly to not do that. People always say "well, why not tell them what you want" but how long can you continue telling people to do things normal adults are supposed to just do? You can only tell people what to do so long and they will keep forgetting and forgetting until you get into a shouting match with them or do something drastic. And the funny thing is its these drastic measures that actually ensure they do what they should do, being soft spoken really gets you nowhere.