Why did Foreman take the loss to Jimmy Young so hard?

You know BoB Box, When Ali entered the ring that night, he looked overweight and pudgy, there were times that he tried to use The Rope a Dope but his challengers after beating George Foreman were wise to Ali's tactics. I think that we were seeing the beginning of the end for Ali, remember this fight along with the Coopman farce were post Manila. I think Ali left a lot of himself that night in Manila against Joe Frazier. That fight was a life and death struggle.