I don't know, I could shitpost on a word document and make a book, the tricky part is opening the writing software when the insights are coming and transcribe them without interrupting the flux. Waiting the perfect moment though is exactly what prevents many books from being written. I have some pages.
After I drink coffee I can spontaneously write paragraphs of unasked spam. I'm drinking my last cup of coffee now. Look at these texts I am sending, there are so ordinary and boring, I'm gonna do my daily tasks soon which will bring me a sense of fulfillment as opposed to this senseless shitposting. Why am I writing this? To remind you you should aim to be some kind of folkloric creature and not write about ordinary topics like I do when my creativity is inhibited by the coffee.
I think you are experiencing what seems a form of hypomania because of stimulants lmao. Also getting your ideas down is not interrupting the flux. Words are just a method to get complex ideas across to others.
Coffee doesn't do anything to me half the time personally, and I can sit down and write on end as is.