When I went looking for someone to blame for the whole creativity-is-a-totally-magical-process idea, I found Romanticism.
Here's Mark Forsyth in The Elements of Eloquence:
"The Romantics liked to believe that you could learn everything worth learning by gazing at a babbling mountain brook, or running barefoot through the fields, or contemplating a Grecian urn. They wanted to be natural."
Mark's adding some sarcasm, of course. He’s English like that. There's a more stripped-down explanation in Brittanica.
"Romanticism emphasized the individual, the subjective, the irrational, the imaginative, the personal, the spontaneous, the emotional, the visionary, and the transcendental...[there was also] a preoccupation with genius."
That's a preoccupation we haven't shaken. We love geniuses and genius itself - the idea that (at any moment!) we could be struck by a revelation that could change everything. These moments do seem natural, as if the insight dropped out of the sky.
Once in a while, you get a glorious and bright spark of genius.
But after you get the spark... what do you do with it?