We can accumulate a great deal when we write. This is an awesome thing. Usually, though, we lose track of our organization over time. When things get hectic, or when you have documents that don't really have a place just yet, they sort of get tossed in a pile to be dealt with later. Then we forget to deal with it.
Eventually, "later" will come. Go through your old files. Reorganize them. Give those uncategorizeable pieces new categories. See if a new organization system would make it easier to find things.
The reorganization has a double use. It makes you see your old stuff again. You will find things you forgot you ever wrote. You'll find things you love and things you will hate (and they will all be your work). But in either case, they will serve to remind you who you used to be and who you have become, both as a writer and a person.
So go and clean out your files. When you're done with that, go write so much stuff that your files fall into organizational disarray again.