According to my shrink, yes, you create new behavior pathways, but that doesn't stop the underlying chemical imbalance, so in 30 years, if you and phillies and I are still alive, we can still bitch about our meds. Yes, we will be on them for life.
However, if you're on a cocktail that's working for you, chances are it will keep working - I've been on basically the same one for about 15 years, and for the most part, it's worked well. And, as you age, (I don't mean like next year, and I don't mean when you're my age, but when you actually become a senior citizen) the good news is that mania tends to decrease. (Of course, there can be no good news without bad news, which is that depression remains, and can be more prevalent).
In any case, yeah, we're stuck. It's kind of like having diabetes of the brain - one may be very well controlled, but only if one takes the meds and does all the other junk as prescribed. without a new pancreas or a new brain, there is no cure.