When I was very young, people labeled me quiet... and some still do to this day.
Labels are subjective and often used to help us process the world around us. A grocery store is a place where labels are not only helpful but appropriate. Someone with an allergy needs to avoid certain ingredients; others want to steer clear of unhealthy additives. When we label someone it's never helpful. Instead, it tends to blind us from the richness and diversity of life.
A label defines a person on a single thing; it doesn't allow for complexity. For instance, two people can have an interaction with the same person simultaneously. One person might think he is the life of the party and the other person might say he is rude. First impressions aren't necessarily correct. Human beings are a mixture of thoughts and feelings. On any given day a person can be dealing with issues unbeknown to us and come across as irritable. Remember we all have our ups and downs.
I admit- I am quiet. But I dare you to sit next to me during a sporting event.