Charles Horton Cooley developed the theory of the looking-glass self, which states that a person's self-concept and personality are shaped by their perceptions of how others see them. According to Cooley, this process has three steps: 1) imagining how we appear to others, 2) imagining others' judgements of us based on that appearance, and 3) developing feelings about ourselves based on those perceived judgements. The author describes struggling with insecurity and a negative self-image in their youth due to overthinking how others might perceive them, as described by Cooley's theory. They have since learned that maintaining a positive outlook prevents assuming others dislike them and helps develop a healthier self-concept.