This phrase has never made any sense to me. It’s a circle. If one side is moving right, then the opposite side is moving left. So the phrase only makes sense if you specify which side we are talking about, which nobody ever does. Therefore it’s completely illogical to me while everyone else just gets it. Side note: Autism can be a real bitch sometimes.

Edit:

1. Some people don’t understand how I can see a problem. That’s cool, but don’t be a dick. We all look at the world through different lenses.
2. This is when I was a kid “helping” my grandfather in the garage. I’m older now and understand that “righty tighty” references the top of the rotation.
3. Some people rotate their perspective 90° and imagine themselves standing on the screw. Therefore when your face rotates to the right the screw is tightened. I hadn’t ever thought of that. But I had imagined rotating my perspective 90° the other direction –the top of my head as a screwdriver. In that case, “lefty tighty”