Have you ever seen those big, red, rolling tool boxes? The ones with all the drawers? Those are exactly the wrong way to think about how we store all the mental tools we use throughout our day. Our mental toolbox should be more of a workshop with all the tools hanging on the walls where they are easy to get to and, more importantly, easy to see.
With the big, rolling tool box everything gets separated into its own drawer based on the purpose it is used for. We may think of one idea as a writing tool, a second as a productivity tool and another as an educational tool. Really they are just all tools, they are good for different jobs, but they can be used outside of their usual context.
Take a screwdriver for example. The intended use of the tool is to tighten and loosen screws. However, a screwdriver is also invaluable for prying open stuck paint cans, scraping dirt out of a tight space or as a wedge to hold something open.
Another example: As has been mentioned in the past, I play roll playing games. One of them uses a system of aspects to define characters. Earlier today I was wondering why it was so easy for me to develop plots for this game, but so hard to do the same thing for writing fiction. The aspects where the key. This tool could be used to create the characters and places for a novel as easily for the game, and like in the game could then be used to show points of conflict that can lead to interesting stories.
The tool was not made for writing, it was made for playing a game, but it was in my tool box. When I stopped thinking about it as a gaming tool and just thought about it as a tool, I saw another way to use it. Sometimes we have the tools we need to solve the problems we have, we just need to take off the labels and leave them where we can see them.