New users do not yet have the vocabulary to understand the app. However, People start using an app with different prior skill levels. As User skill level increases over time, so does their vocabulary. With this new vocabulary, they are able to conceptualize and express desires that they couldn’t express before, so User goals change over time.
When working with clients, I often Use a badging system as a method of actionable user research to gain that shared vocabulary, whether or not we implement the system.