In any kind of social situation, there are two considerations you may have:
“What do I want?”
“What do you want?”
Many of the problems people have dealing with other people come from leaning too heavily onto one or the other of these.
When someone is too nice, or too big a pushover, or too unassertive, it is generally because he is overly focused on the question of “What do you want?”
When on the other hand someone is too rude, or too pushy, or too imposing, it is generally because he is overly focused on the question of “What do I want?”
Getting this balance right is a major milestone in better social results.