I just read the article - and was (pleasantly) surprised that I was going to answer similarly to their descriptions of what eventually became museums...the personal collections of sculptures and decor that peoples had loved enough to put together in a way where they could enjoy viewing them again and again. This could have been in gardens, or in homes on special pieces of furniture, etc.
I enjoy displaying the things that I love all over my home - but I don't care if they are something of monetary value to someone else, or if it is something that I found on a beach and might only be beautiful in my own vision. I think my decor is my own type of museum. It makes me happy, each piece has a meaning and/or purpose...and I can find myself "lost" in a corner of the house while looking at every little shell, crystal, wine cork, glass bead, owl, gargoyle, faerie...it can go on - it *does* go on! :D
The owners of beautiful collections also received a boost to their essence when they could "show off" their valued acquisitions to others - so it is practically a natural evolution to create a "museum". As an artist, having one's work displayed in one of these museums gives us a sense of accomplishment and affirmation - to see someone stare into one of our own creations, see the same thing we were seeing when we were creating, or seeing something spectacularly different - it urges us to create more, to want to share with more people, to have others "experience" what has come from our imaginations.
I just gave one of my paintings to my mom as a gift - and though it is nowhere near a museum right now - it feels wonderful to see it up on a wall, and most of all, to see her smile as she gazes at it every day. :D