I suspect a lot of people have difficulty recognizing that what they believe about the world may not be representative of how the world actually behaves. I certainly do, frequently.
Like with politics, people think they need to go vote and march and stuff to effect change, but if you're willing to accept the idea that there are limits to your ability to perceive the world and your perceptions are misleading, you can pretty reliably go and see that isn't true.
You can also decipher deeper realities like you can basically put whatever you want on flat bread, or that you dadskf;'akse'wfaegqrwt;'lj'a fuck my brain. I'm asd I'm not sure what I was trying to say.
That's my thinking. Most of the PIR aren't very impressive and they're just looking for that temperature change, it doesn't matter which direction. I actually wonder if maybe the paper trick works when it does because it moves the air flow from air conditioning around.