When my oldest kids got old enough we started going backpacking. I started a myth with them that I had put 2 pops in the outlet of various, or all, of the lakes in Washington. As we hiked up the trail I would say to them that “those pops sure will be good!” When we got to the destination lake, I’d tell them “I think those pops are over that way. You guys look over there near the shoreline of the lake, and I’ll go over the other way.”
Above, Laura 8 and Deah 11 at Stuart Lake in Washington. I’d pull the two pops out of my pack and place them under a rock in the lake, out of sight of the kids. Then I’d call to them “I think they might be over here.” They’d come over to look, and find two shiny luke warm pops in the water! They never noticed how clean the pops were!
I assumed they had figured out the ruse, and when Laura was in her mid 20s I mentioned the myth of the pops in the water, and Laura was shocked that the myth was not true! She immediately called Deah to compare notes, and they agreed that they both had totally believed the myth of the lake pops.