Here are a few short ones (all I have time for right now, apologies) but they may keep a certain sort thinking, chewing on them, for a while in spite of their brevity–
“The sense of place is very highly developed in Southerners.” The Habit of Being, p. 520
“You are always bounded by what you can make live.” ibid.
“I hate the racket that’s made over a book and all the reviews. The praise as well as the blame–it’s all bad for your writing.” ibid, p. 517
“The less self-conscious you are about what you are about, the better in a way, that is to say technically. You have to get it in the blood, not in the head.” ibid p. 518
“Writing is a good example of self-abandonment. I never completely forget myself except when I am writing and I am never more completely myself than when I am writing.” ibid, p. 4
“I think the basis of what I see is comic regardless of what I do with it.” ibid. p. 400
[Funny (!) ? The last one is a ringer for how I feel too, and the one about losing oneself in the writing. For me, that's when I know I'm "onto something" (per Walker Percy's "onto something." Percy, another great Southern novelist, i.e., The Moviegoer--Percy was a contemporary of O'Connor and she marveled at his work, thought very highly of it.)]
OK, one for the road, send you away with a laugh–
“P.S. I thought a bloody semicolon was for a long pause. What is it for?” ibid. p. 420.
[She couldn't spell worth a damn either and all of her life didn't see the point of striving to learn the correct spelling of anything as long as she could get HER point across.]