Lucky you. That means you have a very focused work environment with very little distractions. Unfortunately the work I do pretty much forces me to have 10's, regularly 100's of documents open at the same time and to be able to memorize what bits that are relevant came from which document. This is getting harder with advancing age so I used a scrapbooking plug-in to keep track of the citations. Now it is just a file with a bunch of text snippets and hyperlinks.