[D-fendr]

I believe your problem is that you are trying to perceive potential energy as a stand-alone property. It is not; potential energy is a delta.

I believe you've nailed it. Many thanks, grasshopper...

[TXnMA]

You're welcome -- but no thanks needed. As you can see, I was having fun re-visiting past (ca 1964) glories and analyzing them to put words and images around the concept under discussion...

And my Bride of (then) three years (for whom I carried the backpack on the Fujiyama climb) and I enjoyed reminiscing about our adventure.

Indeed -- thanks to you! I enjoyed the "trip"! '-)