Our raw material, the brain, is a network of nerves connected to each other. Our memory is imbedded as active connections in the pattern. When we rely on routine problem solving, experience, proven strategies, we use the paths of connections in our brain that we have used over and over again, The paths becomes like wide freeways. The advantage of these routines is that we can use them rapidly. The disadvantage is the routines ready availability prohibits us from exploring alternatives.
Alternatives are the unused connections in the brain.
The trick to being creative is to get off the freeway and look for surface street connections to our goals. We need to go exploring by getting new stimuli. Without new input we will continue to cook old soup with old bones. New information not only adds to our brains data bank, it also triggers new associations, connections and ideas. The nature of the stimuli is also important.