 That modern media narratives look for a cause, an explanation, an ephemeral Occam's razor, the single winning hot take. Reality usually has more than one thing going on. In that previous debate, Joe Biden dealt with his age for sure. He dealt with coming off a cold, maybe antihistamines. He dealt with, as his staff said, what was later in the day, a sweet spot is usually in the strong parts or the working part, the fat part of the day, not after he's had a hard day of being president.