A personal statement for a college application is often/mostly narrative and descriptive writing. However, you are still making a central argument/claim/thesis about yourself. The best college essays focus on a clear central argument that is supported with personal narratives and details. Whatever prompt you choose, you will have to decide on your central argument/claim/thesis for your response. This statement should also reflect your absolute best writing with rhetorical choices that appeal to your audience. This is a real-life application of ideas about rhetoric.