What is up with this fluctuating page rank business?

I am quite fed up with the way Google arbitrarily changes page ranks. I have been posting with increasing regularity on this blog for the past 2 years or so, and my page rank has actually dropped. I couldn't believe it when I saw it. Simply amazing and oh so frustrating. I am doing lots of reading on how Google decides to put a value on a page/site and the more one reads, the more complicated and hopeless it seems. I mean, unless you are a software guru, there is no way one can understand any of that goobly gook. Here are some of the better and more understandable articles on page rank on Web Workshop, Web Pro News and Page Rank 10. Good Luck!