Some go quite awhile between pdoc visits for a variety of reason$, and when one visits his or her pdoc, sometimes having and knowing one's patterns of ups and downs and their duration helps you and the pdoc make some good choices regarding medications. The DBSA and Mood Gardens site have downloadable charts if you're interested in pursuing this line of thought.
Some people have arrived at their ideal (if there is one) medication cocktail and all they need is a bit of tweaking once in a while; I think that status only comes about after some time in one's bipolar "career." However, in the early stages of medicating this disorder, the importance of fluctuations is greater because there are important choices to be made at the get-go.
