I try to write into the heart of experience. Then, through the experience of the writing, that heart reveals itself to me. To write it down for others, as a door to go through it they choose, is the price of the experience, the price of the ticket. This is the demand that God, if you like, puts on you for being an artist.
These things - the degree of vulnerability, the degree of skill, the degree of the longing to give - are influx all the time, And to lump all that under the word "creativity" assumes something much more static than it is. That's why an artist may be marvelous in her 20s, and be creating automatic crap in her 40s. A writer may be trivial in his 20s, and be writing incredibly in his 50s, because those things are always in flux.
An artist doesn't depend upon inspiration or have to have it. An artist doesn't depend on mood, certainly not if you're earning your living with it. One of the definitions of a professional is you can do some writing if you have to, even in the most extreme situations.