Camcorder is a good idea....but let someone else (wife) do the video, you do the listening and asking.
Don't let the walk-through guy tell you and show you stuff...have him let YOU do the stuff. Actually get your hands on everything and operate it yourself. Watching and listening is ok....but doing is a better way to learn and remember.
Don't let your ego get in the way of asking and asking and asking until you are confident that you understand..
Nodding your head, "yes," while inside you still don't understand is not a good idea. Make the guy earn his money.