The Inner Voice
I think everybody has an inner voice. The difference between folks we think of as "creative" and others is that creative people listen to that voice, take it seriously, and act on it. I know a lot of people who insist they are not creative. My guess is that they're not listening to their inner voice — or that they scoff at what they hear.
I've seen young children decide to create figures out of a ridiculous assemblage of household items — and turn it into meaningful artwork embodying a unique vision. In contrast, lots of people tell me they've had some sort of unique idea but just haven't gotten around to making it happen. As Woody Allen said (paraphrasing), "90% of success in life is showing up."
As the Backstage Man says, "Inspiration can strike at any time. its like friendly lightning." That inner voice of yours — that's inspiration striking. All you have to do is pay attention.