Great Idea Gail!
Might I suggest a 4x5 vinyl covered spiral notepad for your pocketbook? I carry one to record dates, time(s) of symptoms, change of meds, etc. I get so busy sometimes I will write something in mine and will look back at my entry later and realize a new or different pattern. Also, it's always handy at the doctor.
I also have begun my own personal legacy journal. This is something I do in down time when I don't feel like doing anything else because of fatigue/pain, etc. I pull out a picture from a photo album and try to relate an experience, sight, sound, poem, song that relates to that specific picture. It helps me through the rough times and gives my descendants who will never know me an inside view of my life and yes, I include CD experiences as well.
I told my husband, one day I will write an Erma Bombeck style book between the Murphy's Law side of my life/family and the CD combined! I'm sure it would be on the top of the booklists!