For naturally quiet people, the fear of speaking can arise from a few bad experiences, especially at an early age. When an adult reacts angrily or dismissively to an attempt at self expression, it’s natural to take it personally and shy away from future expression. Even if this only happens once or twice, people tend to exaggerate these incidents until they become mental monsters. Growing up, it took me a long time to realize how self centered people are. The way someone reacts to something you say usually has nothing to do with you–it’s more likely a reflection of the mood they’re in or a recent event in their life.