Building a Princess Saving App: How to Build Learning and Fun into Your Applications [pdf]

It seems to me that the big disconnect here is this:

When you're the game developer you know exactly what the user wants to do. They want to advance through the game and have fun. You can make early levels where the player learns one new skill at a time, so as not to overload them. And then when they're ready you can hit them with more complex challenges.

When you're developing some kind of productivity app, a word processor for example, you don't know specifically what your user wants to do. Maybe I want to write a novel? Maybe I want to create a brochure? Maybe I want to insert tables and graphs into a business document? How do you guide me through when you don't know where I'm coming from or where I'm going?