To understand MLC more, I've been steeping myself in literature on Carl Jung's theories on individuation. For those of us at a certain age, this is a period where we and our spouses reexamine the old truths and find out which ones we embrace authentically.
For familial and personal reasons, my W never quite achieved healthy individuation, which has led to certain resentments and annoyances as she expected me to live a life not authentically mine...and blaming me for her unhappiness.
At least that's my hypothesis, but to quote Nat King Cole again, "they try to tell me I'm too Jung."
This is very interesting Paco, perhaps I will follow in your readings as well.
My personal belief/experience is that MLC is only really noted as a "crisis" when there is a major depression element. FS mentioned it being more of a "transition" that all must go through. This, to me, makes sense. Everyone goes through the transition of individuation, but if this time is met with a blockage and depression - that's when MLC becomes the more obvious crisis we observe.