As I said earlier, being in remission and having insight into what triggers relapse with the best will in the world is not guarantee of future remission.
Not least becuase there are cases where prolonged stability is not a feature of that individual's presentation.
My later mother in law (here in Italy as coincidence would have it) had bipolar I. Her condition was enitrely unpredistable. Except for one thing. Stability, even when on a "to the minute" meds regeme, would only ever be a place she breifly visited when travelling from one extreme to another.
It is true that some people relaspe because they don't take their meds, (often for understandble reasons, the side effects can feel a whole lot worse than mania or depression, and that is before you take into account the physical side effects), but what also happens is people stop taking their meds... becuase while on meds they have become unwell. In other words the meds didn't hold their stable mental state, they slipped into mania/depression, and in that altered state no longer took their meds. But the destablisation preceeded the lack of meds. Med taking is not a magic bullet.
In the last year of MIL's life she went from manic and psycotic beyond all belief (We staggered around for months on no more than 2-4 hours sleep a night becuase she was too strong for us to keep here safe in shifts.) with a brief period of calm (a few weeks) then down into depression than resulted in catatonia. She took the meds the whole time. I was half dead with exhustion, but between us we checked, doubled checked and gave her her meds, checked they were down. Right until the end when she was in hospital with pnumonia, thanks to meds she aspirated, and it was too late.
Smetimes the illness is so severe that all the person and their family has in their future is a hellish yo-yo that only ends when grief and a funeral takes its place.
That is one reality of bipolar. Stephen Fry is another. In terms of what day to day and longterm reality looks like, the two have only a lable in common in terms of impact, outcome and potential for a happy(ish) ending.