I can only completely agree with respect to the earlier posts. Ennis fears change, fears being branded "different," and ultimately fears that any difference will bring about a beating. He can't see the benefits of trying "something else." Jack may have been more willing to find a way to establish a more permanence in the relationship with Ennis; but he, too, feels the responsibility of a wife and a son and a life in Texas.
They seemed to have experienced a time when there were no intrusion from others, themselves, or life's burdens, only once. When the greatest worry were the coyotes. Jack may have overly simplified the complexity of their love, when in anger he refers to this idyllic point in time, a point in time etched onto their beings, which they could never go back to or discover again, "All we got is Brokeback Mountain... that's all."

I tend to think that both Ennis and Jack believed they shared much more than those two months; yet, were painfully unable to recreate any semblance of that time- in which they gave only to each other, assisted only each other, took only from each other, and thought only about each other. Yes, those were good times. But the product of that mountain was a love; much greater than anything they had ever experienced before and something which was more significant than anything they would ever experience since.