“I do not know what I think until I write it.”
“I don't know what I think until I write it down.”
“I write because I don't know what I think until I read what I say.”
“...I have to write to discover what I am doing. Like the old lady, I don't know so well what I think until I see what I say; then I have to say it again.”
“How do I know what I think until I see what I say?”
“How do I know what I think until I hear what I say?”