What about in LJ Memories?
Is there any reason you have some in bookmarks and others in your LJ Memories?
I have 9 LJ entries in a folder called "Reference," which are all either questions from here that I've found to be extremely useful, or posts in school communities that I refer to constantly for information. :)
As for Memories, I only have one that isn't mine, and that's one that belongs to a friend of mine that's pretty much linked to mine.
Bookmarks are for impersonal posts, while memories are for personal ones, or at least ones I've written myself.
EDIT: And how did I hit the "?" twice at the end of one of my questions? I am so ashamed. :P