Actually I've been told (by my pdoc) that what you describe is the more typical experience. I had episodes (manic for a few weeks then depressed) every 5 yrs, had a stretch of ten years of "normal" then went back to the every 5 yrs. deal until 2010. At that point I found myself having a manic one year after the last. That's when I decided it was time to stay on meds. I've been without a hospitalization since 2011 so I'm hoping I can keep it that way.