BREAKING: President Biden says debate performance was the result of his foreign travel (CNN)

[andym]

89. He says it's because he was sleepy-- he traveled in the wrong direction

He said he practically fell asleep on the stage. His handlers stated that Joe was just exhausted after 4pm each day.
As for his jetlag:

He was in Europe where time is later, so when he came back it was even earlier than normal. Looks like it was still affecting him more than a week after he came back.

He should have traveled west to Hawaii or Asia so that when he came back it, his body would think 7pm was more like 1pm or noon. Perhaps he should do that for the next debate.

There is a related idea that Joe is old and older people tend to be more alert earlier in the day.
discussed here: https://www.democraticunderground.com/100219085122
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4067093/#:~:text=Older%20adults'%20peak%20performance%20on,to%20be%20in%20the%20afternoon.
Look Out – It’s Your Off-Peak Time of Day! Time of Day Matters More for Alerting than for Orienting or Executive Attention