Answer:
Nobody knows they are doing bad things. They do what is most appealing to them. Not necessarily rational, but the person's primary interest. So, it depends on the person. "Bad" is completely subjective, so it depends on the situation and the parties involved. As a general rule, however, there are seven common reasons.
Hurt.
Fear.
Insecurity.
Inclusion.
Exclusion.
Guilt.
Shame.
Grammar is how you speak
If we did not have grammar people would always talk in slang or not in complete sentences and it would be hard to understand each other
