I've changed mine numerous times over the almost twenty (!) years that I've been collecting as an adult. The first was probably relatively early on when I decided that, if I was going to end up with a couple of hundred ponies, I should decide on a focus. The focus that I chose was to decide to collect ponies rather than ponies and LPS and Pound Puppies and action figures and etc, etc.
(couple of hundred ponies...teehee)
|See-through ponies were not on my original list...|
|...Neither were molded symbol ponies...|
|...Or Sea Ponies.|
|Can-Can line of Shady pose ponies|
Just remember: Geek Cave =/= TARDIS. ;)