3 ideas
A story is sparked by joining two words that are distant enough in meaning that no ordinary association already links them, such as 'dog' and 'wardrobe'. Because the pair has no ready-made connection, the imagination has to build a relationship between them. Connecting the words with prepositions ('the dog with the wardrobe', 'the wardrobe of the dog') produces the first situations of a plot.
You take an ordinary subject and a surprising predicate and ask what would follow, for example 'What if Reggio Emilia could fly?' or 'What if a man woke up as a cockroach?'. The absurd premise stays fixed. Then you work out its consequences logically and in realistic detail, and the tension between the impossible premise and the rigorous consequences becomes the story.
A single word dropped into the mind acts like a stone thrown into a pond. It sets off chains of sound-alikes, memories, images and associations that spread in many directions at once. Seen this way, imagination is a series of reactions you can deliberately trigger and follow outward from one stimulus, not a mysterious gift.