If only it were that easy.
Remember when you were a kid and asked that theoretical question: if you were stranded on a deserted island and could only take one thing with you – what would that one thing be? This is sort of what it's like to move into an RV. Its not that you can't have “stuff”, its just that you need to be much more selective about the stuff you take since storage space is at a premium. You want to make your choices count. Gone are the days of huge closets and half-full drawers. We are into space-saver bags and magnetic spice containers for the outside of the refrigerator – every inch counts.
Don't be afraid to try again and again.
One benefit of our house not selling was that we had time to try things out. We would take things for a trip and if they didn't work, they went to another category. If we didn't miss something on a trip, it never made it to the RV; it went straight to one of the other disposal categories.
There's a lot of trial and error. Yes, I have disposed of something and then needed it a month or two later (plastic table cloth – duh!). Yes, I continue to move things around to try to find the most efficient place to store things. If something is too big/small/clunky/inefficient, get rid of it and/or replace it. Your space is too valuable to waste on something that isn't working for you.
Look for new ideas everywhere.
We struggled the most with our clothes – having to move between Iowa winters and summers plus needing to have some business attire is challenging. We are still trying to perfect this balance. We replaced most of the hanging space in our master closet with a custom closet organizer since most of our clothes are not hanging. I am constantly looking for organization and space saving ideas. Pinterest and HGTV are great for these types of ideas.