I've always felt that I wanted to write my own system to manage my blog or whatever. And I did for a while. I coded a pretty decent job that gave me everything that I needed. However, with work and various other stuff catching up quickly I decided that I couldn't really afford the time to keep it secure, and keep innovating, etc. even though the ability to tell folks that it was my own creation was something of a pleasure. Of course the main pleasure was knowing that I did something pretty unique and was able to play around with the code as much as I wanted as I knew it pretty well!
So for my newest site and redesign, I've gone "backwards" and am using wordpress. For many reasons, see above, but mainly out of laziness. There is a huge community of developers with more time than me to be worrying about security and everything else, and I've found that its well able to suit my meager needs. More than able in fact!
Of course, any spare minute I get, I've starting changing bits of the code here and there... changing anything that didn't suit me. So again it starts... Us code monkeys don't really need to sleep anyway....