I keep a journal of my symptoms every day as the bad day symptoms are easily forgotten when they are split by the good days, and when I've attempted to relay the many problems to the Dr I can't remember them all.
It's a really helpful tool to have when, on some days, even your name becomes a jumbled soup.
If or when you start it is a bind to write it all down, but it soon becomes a routine. I find myself going to my diary three, four, five times a day logging times when symptoms come and go. Some days, apart from my persistant problems, all I write in is "A good day". My persistant problems I write in as my own kind of short hand every day, but I know what they all mean. Eg.....SNR-TLNF...... stiff neck right - tingling left neck and face. Fairly basic but I know if I have missed one of my "codes" out then on that day I didn't feel it. Intermittant symptoms or unusual symptoms I write out in full but on the days where I have lots of problems I tend to only jot down the strongest symptoms and some of the less painful one I skip.
Good luck with the SSDI hearing and heed your attorney's advice and start a diary, it's a very useful document to look back on.