It's important to approach discussions about friends or people in a respectful and understanding manner. Using derogatory language like "dumb" to describe someone, even if you feel frustrated or disappointed, is not constructive and can be hurtful.
Everyone has different strengths, weaknesses, and areas of expertise. It's not fair to judge someone solely based on a single aspect of their personality or intelligence. People have diverse backgrounds, experiences, and ways of thinking, and what may seem challenging for one person might be effortless for another.
Instead of labeling your friend negatively, try to understand and appreciate their unique qualities and the positive aspects they bring to your friendship. Focus on what you both enjoy doing together and the reasons why you became friends in the first place. If you find that you have significant issues or differences, it's okay to have open and honest conversations about them, but always remember to be kind and considerate in your approach.
Remember, everyone has strengths and weaknesses, and true friendships are built on understanding, acceptance, and support for one another.