It is hard to define creativity; indeed I have never seen a satisfactory definition. We recognise exceptional creativity, and exceptionally creative people - but nonetheless it is hard to say what creativity might be.
That suggests to me that creativity is a very fundamental attribute. My understanding is that creativity is the action of free will.
In other words, there is a backdrop of events that follow a cause and effect logic - but creativity is when these chains and webs of quasi-mechanical unfolding are qualitatively changed by the operation of autonomous choice from a being with free will.
As further clarification, many or most or perhaps sometimes all f a person's choices are not made by their true self using free will; but are automatic, conditioned, quasi-mechanical responses due to 'false selves' such as the public personality. The real self in an adult is typically a hidden and enfeebled thing; buried under habits, socialisation, instincts and much else.
I think that this may be a relatively rare occurrence in the lives of most people, and that high levels of creativity are therefore rare. Geniuses are among the rare people who seem to have a greater access to their true selves, are in frequent communication with their true selves: this is the integrity of genius, which shines out from so many biographies of geniuses.
Good or bad, nice or nasty; a genius is an integrated personality; highly autonomous from other people is his views and motivations; one aware-of and dominated-by inner drives; one whose decisions, evaluations, choices are distinctive and highly independent.
Geniuses are 'inner' people; and this innerness is, I suggest, the source of their creativity. It could be said that geniuses are made (are born) such that they are connected with inner sources of thinking, including being connected with the real self.
Of course, geniuses have free will just like everybody else - and the born genius may choose to reject his destiny, and not to use his special abilities. But in this respect the genius is just an extreme of the universal situation.
If creativity happens when free will intervenes in reality, then geniuses are simply those who combine a high awareness of the operations of their free will, with exceptional ability. Presumably anybody and everybody can and sometimes does 'tap-into' and use their real self in making autonomous choices; but the non-genus does this seldom and easily ignores or rejects the consequences - also the non-genius may have merely average (or below average) abilities; so that the fruits of their creativity is of little interest to other people.
But, whether or not it is impressive or influential, actual creativity is simply this process of using free will of the real self to choose. Creativity 'has happened' if this has happened - whether or not we know about it, whether or not it has a measurable effect on human affairs.
(Conversely, what may appear to be a 'creative act', impressive, influential, widely admired or useful, is not truly creativity if it is not a product of free will, if it does not eventuate from free will; if it is merely the product of quasi-mechanical unfolding of cause-and-effect processes.)