When I first implemented GTD my task was mammoth - I had boxes and boxes of stuff to deal with. I arranged some of those three-shelf folding bookcases to form a corral, piled in all the stuff I wasn't going to get to anytime soon in the corral, and covered it with a king-sized sheet. I put it on someday/maybe to "process the corral." I think over two years I had to go look for something in there once or twice. Finally I had a weekend to deal with the corral, and it was gone. Meanwhile I had the daily stuff in the GTD system at the "brown belt" level or close to that from the start.