Heard when young, an interview of "The Greek Musical Tycoon": to state that compositions are heard in his own mind, and they are polished there too.
If you don't write things down on a piece of paper, they will be ready for you when you need them, like an exotic joke "Jol Myun", when you cross the right street.
However, papers do accumulate. They are the result of nervous scribbling on trains, in the bathroom, and after dreams. These scribblings, when entered into the computer, do become most of the precious "filler" of compositions.