It breaks my heart to say this but my father was diagnosed with dementia few years ago and he has been battling dementia ever since then. Before we insisted on taking him to the doctor, we could see a lot of signs that made us think "can it be that?". My father is Albert Einstein compared to Biden at the debate.
If you think "Biden just had a bad night" or "He just had a cold" then I regret to inform you that is copium and you are coping. There is no fucking way in hell that was just one bad night or cold. There is no fucking way in hell his cabinet or DNC has not been aware of these issues for at least couple years.