Seth Meyers has officially had it with Trump’s talk about wheels and walls.

Of the many bizarre things the president has been repeating during his shutdown fight is some version of this analogy, that he presented to reporters during his trip to the U.S.-Mexico border on Thursday:

“They say a wall is medieval, well so is a wheel. A wheel is older than a wall. And I looked at every single car out there… and I said, do they all have wheels? Yes. Oh, I thought it was medieval. The wheel is older than the wall, you know that? There are some things that work. You know what? A wheel works and a wall works.”

Leaving aside the fact that the wheel is not, in fact, “older than the wall,” the Late Night host had another, more pressing question. “I’m sorry, you have to look at all the cars to confirm they had wheels?” he asked incredulously.

“But seriously, what is wrong with your brain?” Meyers asked. “I mean, did someone replace your Diet Coke with Nyquil? Honestly, how long until he just starts reciting nursery rhymes? ‘The buses, they all have wheels, folks. And the wheels on these buses, they go ‘round and ‘round. All through the town.’”

Turning more serious, Meyers added, “Trump is frustrated because he’s not winning the argument and even he knows it. He spent three years making the wall the signature promise of his campaign and his presidency and it got nowhere.”