Geez ashi! What a topic!
Am I stable? Depends on your criteria I guess. I've been quite mentally ill in my time but I was never legally non compos mentis. Are you stable if you're reacting to extreme stress under extreme conditions? Are you unstable if you don't realize your conditions are extremely stressful because it's the only way you've ever lived? Are you unstable when you have some paradigm shift after getting more information that causes you to re-evaluate everything you ever knew and felt and believed? Does 'stability' have anything to with how mentally ill you can become as a result of life's stresses?
While I was going through many of the changes, I worked, raised kids, served my community, had a social life. Then at one point the stresses piled up to the point where I could no longer function in many of those areas. I had to stop and work on learning to change the stressors and to deal with them more efficiently.
I didn't feel stable at that time. I still managed to cook, clean, tend my little son lovingly. Was that stable behavior?
Hmmm. I've shed a lot of words and little light haven't I? Sorry, I don't have 'an answer'. All I know is, stability is relative to your entire condition/experience/circumstance.
ANd am I stable now? Don't ask, don't tell!
Love and big hugs,
MD