I have kept a journal or diary of some sort for about 18 years. Yup, I started young. I haven't always been faithful, and it has changed styles several times. I started by keeping track of very common, everyday activities such as "got up. got dressed. did chores" on American Girl calendars. Then I pretended to live in another year (like 1835) and kept an "authentic-to-the-year" diary. (That didn't work very well. How does one describe traveling 2 hours away in 19th century language?) Finally I quit using pencil. That was a very good decision if I ever want to read all those journals again!
Now though, I don't write every day. I don't record every minute detail of my life. I use it as an outlet for my thoughts and getting my brain sorted out. Maybe those authors are right, that a woman's mind is like spaghetti or a ball of rubber bands! I need to get it all laid out sometimes in order that my mind isn't racing 100 miles per hour.