Not to want to say, not to know what you want to say, not to be able to say what you think you want to say, and never to stop saying, or hardly ever, that is the thing to keep in mind, even in the heat of composition.

1 Take a pencil to write with on aeroplanes. Pens leak. But if the pencil breaks, you can’t sharpen it on the plane, because you can’t take knives with you. Therefore: take two pencils.