I have an old filing cabinet in my office that I hardly open anymore, and which I've started slowly going through in search of an old contract that I'm missing (and which, I'm afraid, is probably not findable). It's an interesting exercise, because the cabinet is full of all the papers that I've considered important through the last 20 years or so. Things like: Legal papers having to do with my family, a few years of tax returns, records of the different health insurance plans I've had, legal forms from various jobs I've held (mostly having to do with being laid off) -- and lots and lots of old stories.
Oh, and rejection notices.
Back in the day when you mailed out all your stories, you'd get rejection letters back -- and, as with emailed rejections, they'd range from terse and impersonal to several paragraphs explaining why my story wasn't right for them (or, in come cases, not right for anyone). Sometimes, there'd be a combination; An impersonal rejection letter with a comment scrawled at the bottom.
I'm going to go through all the stories in the file, many of which were sent out to a lot of magazines, and pull together all the rejections. I'm not sure whether I'll just count them, or perhaps scan them in to pore over in my old age, or maybe pull out a few choice phrases and make a poem out of them...