My daughter turned me on to a Facebook group — “Liminal Spaces” — and I’m in heaven. Finally, a word for one of my favorite life circumstances: That transitional space or period, when the situation is no-longer-that but not-yet-what-it-will-be. (Actually, the earliest recorded use of the term — which derives from the Latin for “threshold” — in English dates back to 1870, so yeah, I’m more than a century…