Today’s Bloganuary prompt certainly offers a broad spectrum of potential responses.
At the most pedantic level, think about all those silver-laden Spanish ships that sank on their way back to Spain from South America. Or, going even further back, the hapless King John’s baggage train getting lost in The Wash. Still earlier in history, there are the six wonders of the ancient world that didn’t happen to be the Great Pyramid of Giza.
Somehow, though, I suspect that what’s really being sought here is something a little more personal: perhaps even spiritual.
Sorry, but for that, dear reader, you will need to look elsewhere.
I have certainly lost lots of things in my time: a nice pair of Ray-Ban aviators that fell off my nose into The Everglades; my grandfather’s gold wristwatch that somehow failed to emerge airside from the security x-ray at Manchester Airport; a pair of wireless earphones that I inadvertently left on a train.
But have I ever lost anything that was really precious, but not in a material sense? I don’t believe so. I have love and health and hope and I’m still capable of solving the Wordle nine times out of ten.
I’ve even get another pair of shades (man).

Gone but not forgotten
Somewhere on the bottom of Lake Allatoona there is a pair of my glasses. As you say, those kinds of things can be replaced. What I treasure, and hope not to lose, are friends. Glad to see your post coming up. Happy New Year!