I think he shows the "slowed-down" aspect of his age but fogginess, drifting? No. Don't see it.

OTOH at his age every passing year is going to take more away and six years from now he might not even know where he is half the time.

But this mileage varies. Pablo Casals was at 96 playing gifted interpretation of Bach figured bass pieces for cello and that is extremely demanding numerical musicianship.