A Pillow Book is a diary of sorts. It doesn't just talk about the day's events, but contains lists, observations, conversations, musings, anything the writer feels like writing about really. 21st Century is because this is a modern pillow book, since it's done on a computer.
This is me. This is what my life is all about. I will let you into my head a bit... feel what I'm feeling, see what I'm creating, understand what I'm learning. Enjoy my journey right along with me!