My son was making a 'house' out of a narrow, tall cardboard box as high as the top of his hip. When he climbed into it and stood balancing precariously on the hardwood floor, I said I would help him by moving it to the rug, which would cushion his falls. He agreed, but then immediately objected when I moved it. He was going to move it when he was ready. Presumably after more climbing in on the hard floor. I moved it anyway, and he worked on it for a bit, then climbed in, and fell over on the rug. He was unhurt. My mind started to work up a "See? The rug cushioned you!"
"See?" he said, "That's why I didn't want it on the rug, because the rug makes me fall! It's looser."
I remember when I was in that phase, of always maintaining that I was right, even when I knew I was wrong, following the dictum of Just Say Anything, no matter how silly it is.