Hey i'm here to just mess you up
The belief that people do take you differently from what you are is real. So real....
We most times decide to downplay it. But some people are fully aware they are on the wrong part when dealing with you. But they persist nonetheless...
Though it's part of human kindness to care for people. But what is the use if it comes with pains?....
And someone will blame people for taking off their own shoes. 
The shoes you don't know how it pitches them...
Stop caring when you notice people are taking your kindness for weakness. Trust me they know exactly what they are doing....
To avoid long stories, some people you meet should come with a tag and a warning sign like ''Hey i'm here to just mess you up''...
Yes, there are plenty of people like that. Some of them do so intentionally, some do it unintentionally.
But as you imply, they are to be avoided.
Most of them do it intentionally. And yes just try as much as possible to avoid them