It's less of a creative writing prompt, and more of a creative writER prompt. It's designed to help combat the feeling that almost every writer feels that there is still so far to go and that they aren't actually making any progress at all.
I have prompts about how to define success so that you can look up the mountain and decide which peak you want to hit and how you're going to get there. I even have talked about setting small goals each day to help the march of progress.
But from time to time, a writer (or really any artist) needs to remind themselves of just how far they've come.
Prompt: Look "back down the mountain." Take a moment to list out between a dozen and twenty things you have accomplished as a writer. These don't have to be external acknowledgements (like contests won or scholarships) though they can be. They can be as concrete as a publication credit or as vague as writing successfully every day, the fact that you have multiple stories in your head, or choosing writing over something else you wanted. Don't write out every little thing you can think of ("When I was six I wrote a ten page story for Mrs. Delgado...."). This isn't an exercise in everything you've ever done, but more the things which, looking back, you can be the most proud of. Between 12-20 means you can't just list a couple of things, and you can't list everything trivial--you will really have to think of those things you have done that seem like your truest accomplishments. If you need inspiration, you can see my list here. Try to hit the things that feel like they cover distance. When you are done, gaze in awe at your list and realize that you really have worked hard. There may be more to go, and some days it feels like you're not getting anywhere, but you really have come a long way, baby.