Noir is about flawed people, more than anything else, I think. We may write about them sympathetically or unsympathetically, but the trick is letting the reader in on the flaws. Then, we tell where those flaws lead our characters. Or maybe what I've just said applies to all fiction.
I am a journalist who has covered much of the deep South. As such, I have run into people whose deeds and thoughts read like fiction. What a delightful life!
"Ink runs from the corners of my mouth. There is no happiness like mine. I have been eating poems." -- Mark Strand
In other words, I write because it makes me happy.
Omnivorous reader, currently recommend short stories by Tim Gautreaux, E. Annie Proulx and T.C. Boyle.