Most of the time, we do this without realizing it. As adults, we use logic and judgement to sift through the information. We make comparisons, doubting feedback which seems false and internalizing that which rings true. We also add our own feedback based on our personal successes. I'm good at this.
Children have no such basis for comparison.
They trust their caregivers implicitly. And, initially at least, they apply all parental responses to their self-image. Children who receive consistent affection, encouragement and guidance learn to see themselves as lovable and worthy. With their parents supporting them, they feel safe to venture into new realms and, as they experience success, they become confident of their abilities. They also interpret and react to things from a negative perspective.