Mark60, I've done posse hunts for several persons who hid, then couldn't find something later. And in those cases (and cases of caches that I know of being found), there was very little "rhyme or reason" to the landmarks they might have chosen. Ie.: the fixed object (tree, rock, chimney, fence post, etc....) was not something "un-canny". So in actual real life, the notion you are advancing doesn't seem to hold enough merit to make it ..... as if those "un-canny" things are more-likely to be "treasure hiding spots".
2 examples come to mind (they're just examples, and I know that no 2 caches are alike):
a) I was called out by a realtor, who was preparing to sell a house. The elderly man who owned the house, was well into his 90s in age. In a convelescent home. No longer able to carry on conversations (ie.; advanced dimentia). But a few years earlier, when he still had some of his wits about him, he'd told his adult daughters that he'd buried jars of silver coins on the property. They didn't put much stock into it, and ... at the time, assumed he'd get better and head on home. But his condition only got worse, and pretty soon, a few years later, when they'd ask him "Dad, tell us again what you were saying about buried money?", the man was just too far along in dimentia and old age.
The house was going up for sale, and the daughters told the realtor the story. They rented a metal detector, walked all around, but .... didn't know what the heck they were doing (never operated a detector before). So they searched around for an experienced hunter, and were referred to me. I agreed to go check the property. We had only a few clues to go on, and that was the recollection by the daughters that it was on a "certain side of the house", "near a wall", etc...
I was able to find it. Simply at the base of a wall, beneath a window. Nothing out of the ordinary or unusual or uncanny, etc....
b) Another time I got called to posse hunt for an individual who said he'd buried a plastic tub full of gold coins at a buddy of his' house back-yard. Apparently he was in the midst of a divorce 10 yrs. earlier, and had wanted to hide some coins, "till the heat was gone". He didn't want this nest egg around anywhere near him, so he asked a buddy if he could please bury this at the other guy's house. The 2 men went out in the guys large backyard (a few acres) and chose a spot near the fence to bury it. The purposefully picked a prominent bush, and made mental note , for future sakes, where it was.
But as the years progressed, the homeowner did various yard work. Bushes and trees grew up during 10 yrs., such that .... what might have, at one time, been a "prominent" bush, now there were all sorts of trees and bushes (the man was a green thumb gardener, so it was not unusual for him to plant, prune, etc...).
After 10 yrs, the guy can back to dig up his gold coins. But now.... it seemed that EVERY bush "looked the same". They dug countless holes at what they thought (based on their mental recollections of 10 yrs. earlier) was the spot. To no avail. So they hired me, and I went out and found it for them
Point in each of these cases, is case examples of human nature that .... no ... you don't necessarily seek out "un-canny" spots to hide something. Any fence post, base of a chimney, etc..., tree, etc... suffices.
I have several more posse stories with the same conclusion. And know of caches found in my area, that were simply the result of someone digging a hubcab signal (they thought was about to be large junk), but with no correlation to anything un-canny as far as rocks, squiggles, signs, maps, etc..... I was a part of a "tame" cache, which was simply buried in the floor of a barn. No markers or anything that we could deduce in retrospect . Aside from perhaps the person who buried it, might have simply done it "next to such & such post", etc.... Nothing mysterious or un-canny.