Do you finish your notebooks?

In listening to the Pen Addict podcast(I'm working through their back catalog right now.  If you're any sort of a pen and paper person you should be doing this as well) they discussed the idea of finishing notebooks before moving on to new ones.
I have to admit I'm a bit torn when it comes to this idea.  Part of me doesn't want to waste the notebooks I like so much (and have spent good money on) by leaving parts incomplete.  However the organizational side of me says that it doesn't make sense to go back and fill in disjointed entries on pages just for the sake of filling up the book.
There is a pleasure to flipping through the pages of a completed journal.  Turning each page and seeing the writing, thoughts, notes, and ideas I have captured over time filling the page imbues a certain sense of satisfaction. Again though, having notebooks that are organized and structured, valuable references to the work at hand, also provide a sense of accomplishment.
Apparently for me there is no right answer.  The times I run into problems is when the desire to switch notebooks comes too quickly and my thoughts become fragmented and hard to access. I'm not looking for a system to maintain them in a uniform manner, no rather just a settling point between the pleasure of writing and the desire for productivity.
Do you use one or multiple notebooks? Do you finish a notebook before moving on to your next one? Let us know in the comments.