Actually, I do throw writing notebooks away. One's in the trash right now. But I looked through it very carefully first.
Because the other day, I was flipping through an old writing notebook--one of those el cheapo spiral notebooks they sell at Walmart for a dime each around August--and I discovered part of a story that I hadn't yet typed. I typed it up and went through the rest of the notebook, and found two key scenes from a WIP novel that had likewise never made it from the page to the computer screen. And this notebook was from early October! If I'd thrown it away, those scenes would have been lost forever.
Still no word from any editors, good or bad. Hey, it's supposed to snow overnight! Maybe a whole inch!