What is existential migration? MaryAnne explains this ailment

One day, not so long ago, when we were still in the exhausting throes of impenetrable visa applications and living out of two battered China Post boxes, partly in my parents’ basement and partly in the little house in the big woods where I grew up (the one heated only by a cast iron wood stove and by the fury of my frenzied baking), the man I recently married posed a rhetorical question that I’ve been trying to answer ever since.