It's pretty common I think that the production and acquisition of new toys is a lot faster than it used to be. I used to get toys as a kid twice a year, and occasionally when I'd saved up enough pocket money.
that gave lots of time to enjoy those toys, get to know them and become familiar with them.
these days I get a shipment from somewhere at least once a month and I generally acquire an average of more than one new toy a week for sure. I can see your point Paulbot, it becomes hard to find the time to appreciate each new toy and the old stuff can be just plain forgotten. I too have more than 80% of my collection in storage and probably at least 20%-30% of that is still sealed.
I do rotate, but it's occasional and I try to put newer items on display in the cabinet.
I pick a theme for a shelf and that's what goes there, it's a good way of going back and re-enjoying what's in storage but its not a regular occurrence and I do feel that I'm not making the most of the collection. I hope in vain to have a collection room one day where a greater percentage of my collection will be on display and easier to access.
One of the hardest thing for me to do is say no to a lot of new stuff, it's easy to get caught up in the hype of new toys when there is often little need to buy a repaint and a lot new items are just there to keep a name copyright or fill in some shelf space. I'm yet to buy a Movie 4 Leader Prime, I'm going to get the Takara version when it eventually comes out and that will be the only one of that mold. The advantage of saying no to a lot of stuff is that when some thing comes along like an MP Ultramagnus I can pre-order it the instant it becomes available and I don't have to worry about funds for it, just the space where it's going to go. :p And then it's not lost in a sea of new stuff I don't care as much about, just a lake of cool stuff I do care about.