I didn't do the two-day thing. I started carrying around a notebook for GTD and gradually shifted my organizing systems into it over a number of weeks and months, as things came up.
You might want to do this: Set up a physical inbox. Write on a sheet of paper "process piles of stuff in family room" and put it in the inbox. Then process that: i.e. maybe get that written as an action on a context list or scheduled on your calendar or something, so you can empty your inbox. Or you could identify each pile of stuff in the room and write several separate sheets of paper e.g. "process pile to left of door" etc. Then, think about whether you have any other "stuff" elsewhere that hasn't been collected.
Or, you could get several physical inboxes and slip one under each of the piles in the family room. Then you can say that your inbox is actually several physical inboxes. The advantage of doing this is that it clarifies which things are in your inbox and which aren't, and might also help to overcome inertia in starting to process the piles.
You might want an actual physical inbox, usually empty, in case urgent stuff comes up.
Inability is an abstract thing involving comparison with alternate universes; it cannot be experienced.