Emotions
Human beings vary tremendously in their ability to perceive emotions in the self and in others. They also vary in their ability to identify, articulate, and manage emotions.

If that was not the case you may have grown up without developing the tools necessary to manage emotions appropriately and effectively. In such case you have work to do in adulthood.
This includes identifying triggers that can tie you in knots emotionally and that can negatively impact your personal and professional lives. It means learning more effective strategies for identifying and managing emotions.
Understanding something about emotions in general, and the way in which you tend to deal with them individually and specifically, gives you the opportunity to consciously select appropriate and efficacious behaviors for a given situation.