In my storage locker, I have two boxes full of little scraps of paper, half-filled notebooks, computer printouts and all kinds of things, all filled with my writing from the last 20 years or so. I even have old computer disks.
Every so often, I try to sort them out into some sort of order, and throw away what I really don’t need. The problem is, I realised I need them all.
In the book I am almost finished with, I have used images that I came up 20 years ago, and ideas I had 10 years ago, and lines I’ve found written on scraps of paper from goodness knows when.
I’ve realised nothing I write is wasted. Even if it’s just one line in a notebook, or an idea I had discarded, it all gets used one day. When I have the right story, all those little scraps of paper find a place.
Don’t throw any of it away. Keep it and read it and go over it and one day, even if it’s decades later, you will use it.