Recently I was completing some government paperwork, and I failed to make a copy of one of the pages that I mailed as part of the application. A few weeks later I received a follow up letter asking for more information on that page. Cue sigh of frustration. If I had only made a photocopy of each and every page that I had mailed, it would have saved me hours of time, not to mention loads of energy.
Learn from my mistake and make copies of everything you sign and everything that you even think you might have to follow up with later. If you have a home scanner, scan copies into your computer to reduce paper usage.