The story of "The Bull Elephant" is to illustrate the point of having the "right conditions, the effects will follow".
Notice the blessed one is among a group of people while the bull elephant is among a group of other elephants, the story is similar but have different meanings.
The blessed one being within a group of people does not provide the necessary "right conditions" for the blessed one to prosper. While the bull elephant being among the group does not have the best of what is available.
The story then changes as the blessed one moves away from the group, therefore having the "right conditions" while the bull elephant doing the same seperated from the group.
Then the blessed one being alone and becomes aware of his changed environment, from a group to alone, which provides the right conditions for one to see oneself the difference between a group and alone....."Not hemmed in, I live pleasantly and in ease"
The same process happed to the bull elephant as the bull elephant is aware of the difference between being within a group and being alone and the benefits that comes with being alone....."Not hemmed in, I live pleasantly and in ease".....also uncut grass, undisturbed water etc.
Then towards the end when the blessed one "realized his own seclusion and knowing the train thought in the bull elephant's awareness".....meaning when you know oneself, you will know others.....yet they are both at joy!
Without the right conditions one cannot progress!.....like an apple seed cannot sprout if the ground conditions are not right!
On the subject of the two pains: physical and mental pain.
The blessed one only has one pain that being the physical pain as he is still within the body, the mental pain does not exist as he understands in the mind-consciousness that it is empty.....while the run-of-the-mill person has the two pains being physical and mind, both consciousness.