 Because it seems like he knows what he wants to say. I'm not one to throw stones, but yeah. No. But then his brain will click out and he'll say something that doesn't make any sense. I think it's more that it's not that he loses the track. It's that he can't get back to it. Once he's off, he's off. He's completely off. He tries to come back and it's like, well, that didn't make sense from what you were just saying.