Beck began helping patients identify and evaluate these thoughts and found that by doing so, patients were able to think more realistically, which led them to feel better emotionally and behave more functionally. He developed key ideas in CBT, explaining that different disorders were associated with different types of distorted thinking. Distorted thinking has a negative effect on a person's behaviour no matter what type of disorder they had, he found. Beck explained that successful interventions will educate a person to understand and become aware of their distorted thinking, and how to challenge its effects. He discovered that frequent negative automatic thoughts reveal a person's core beliefs. He explained that core beliefs are formed over lifelong experiences; we "feel" these beliefs to be true.