Thanks for the advice.  I think you may be right.  From the beginning, my plan was to take 1 section every 3 months.  I felt that would give me plenty of time to study...which it does...but it also gives me plenty of time to forget the material. 

I'm shocked that the longest you did was 5 weeks!  Maybe if I gave myself that kind of deadline, I would push myself a lot harder and come exam day, everything would still be fresh.