I make notes as I draw. They're not always drawing related, sometimes I write something down because it's convenient. Whatever I think (at the time) I'm going to need to remember later. At the time, they always seem important, but they usually end up being non sequiturs of some sort. I have no idea why this Sock! note is there. My guess is that I'd written that to remember something about a sock, did whatever it was, then forgot to erase it afterwards. I don't remember, so I really have no idea though.

These notes are usually erased from the boards before their final scan, but a few have made it through, I think. Sometimes they're like a weird backwards history, like what I was doing or thinking about at the time. 

Or like a stash of nuts a squirrel buried and never found again.