As the author of your own life, character development occurs as a process of reflection. If you are dis-satisfied with yourself, decide what you want and start writing your current chapter to accommodate that character.
Everyday interactions are interpreted as slights, criticisms, and injustice. Defaulting to anger, one might complain to fellow sufferers; but rather than expressing their needs, they give in to a sense that they are worth no better.
Negativity is a self-fulfilling prophecy. You don't even have to see the cup to assume it is half empty. A song lyric from the old comedy review, Hee Haw, expressed it as "If I had no bad luck I'd have no luck at all."
Negative energy—in the form of sadness, anger, anxiety, fear, etc.—is unavoidable; it is part of life. But you can limit your exposure to it by choosing to surround yourself with positive people and experiences; and remove yourself from negative circumstances.
Children learn differently from adults. They pay less attention to words and more to emotions. Emotional energy is the foundation for human life, and is therefore what the infant and toddler learn first.