Yesterday, I read an unfamiliar word in a book I won't name: "mandorla". It stuck with me all day and then into the night, on my mind even as I went to bed. Mandorla, mandorla, my last thought before sleep.
This morning, I awoke and sat down to breakfast, one of my words-to-learn ledgers at wing. I opened to the page I had stopped at yesterday (which I had flipped to and bookmarked without reading), and one of the first words on it was "mandorla" -- undefined, as it were, it not being in the dictionary I had referenced after writing the word down (years ago, when I'd first started this particular ledger of new words).
I have not, to my recollection, heard this word except for when I first noted it and then yesterday, in the book I'm reading, approximately twelve hours before I would encounter it in my ledger.
And the clincher: I looked it up tonight, and was unsurprised to learn of it signifying the coincidence and interaction of opposing realities, of which I have recently been experiencing extensively.