I cannot live without pads of graph paper. Anything written on regular blank paper or lined paper is just wrong. It must have the pale blue lines of a proper pad of graph paper or anything I write on it, is rubbish.
I periodically find myself writing something on the latest graph paper pad, only to realize that its not interactive and I cannot edit, so with a sigh I go rewrite the entire thing in a text editor.
Then I go back to the graph paper pad