When I built my first portfolio site there weren't all the free content management systems options there are today. When I decided to rebuild my site in 2010, I opted to start from scratch and completely redesign and rebuild my own content management system. I had a very clear idea of how I wanted the site to be organized and function. It seemed just as much work to build it from scratch as it was to learn and modify someone else's code to meet my requirements.
It's a huge improvement over the previous CMS I had built. Adding, removing, and editing categories, years, and project entries is now incredibly simple.