A user’s goals 1 week into using your app and 6 months are rarely the same. “Elder users” often won’t even retain the goals that they had at the start of their experience. Apps with continued user involvement enable the user to accomplish multiple goals to maintain users through full goal transitions.
New users do not yet have the vocabulary to understand the app. User skill level increases over time, giving the user new vocabulary to conceptualization and express desires that they didn’t have before.
Additionally, people’s life circumstances will change over periods of time, so it’s unreasonable to expect that they will have the exact same needs over time.