Before rationality- a snapshot
Thanks for your kind, encouraging, and thought-provoking comment Willa :)
Definitely the ideal would have been to write this earlier on- the post itself has been on my list to write for a long time, which probably didn't help. I like the idea of having some kind of objective comparison method- the ideal would be some kind of Rationality score, but I don't know if that kind of thing does/could ever exist, or would even reflect the breadth of change one is likely to experience enough to make it even vaguely useful.
I think "dark night of the soul" works pretty well as a descriptor of the experience we're talking about, although to me it conjures some images of being either guilty or having to make a difficult choice, rather than necessarily specifically having your cognitive foundations shaken. Whatever we call it, I would- as you suggested- be interested to hear how other's dealt with it, and how they managed to fulfil their responsibilities in other areas of life when at times everything else can suddenly seem quite unimportant.
Your ideas for avoiding our Dark Night sound reasonable and it comforts me that you seem to be a lot further on in your "thought journey" and still find solace somewhere; I guess my worry would be that lifeboats might not be enough for me to retain enough functioning for the rest of my life, and I would like a reasonably solid intellectual terra firma to act from. I think your idea about self-talking with very concrete, predictable things is likely to help, and I have heard of such things being used for anxiety attacks and the like.
I'm interested to hear what your "snapshot" looks like- even if you're not at the beginning of your journey, it's probably worth doing both for yourself and for other travellers. And thanks again for your encouraging and thoughtful reply- lots to consider!