The most important signs of emotional wellness are how well you cope with regrets, and mistakes, and forgiving yourself. Positive emotional wellness allows you to assign a positive meaning to a negative experience and move on. You are able to let go of regrets, hurt feelings, guilt, etc comparatively faster as opposed to someone who doesn’t know how to maintain emotional health.
Emotionally healthy people can stay in a positive emotional state for either longer periods of time or more frequently.
I channeled the answer to what ‘beliefs’ are biologically speaking. This is a detailed explanation of how you create beliefs and what exactly they are, chemically speaking.