Perhaps. But I somehow think that it was up at LF when Ennis did finally realize how Jack must have felt.
I also believe that the shirts were the final stroke :\'( , but there's another point that we all forget - during his phone call with Lureen, she told him that Jack wanted his ashes to be scattered on Brokeback mountain. I think that even than Ennis has partially come to the point when he could understand Jack's feelings.
So, we can divide the last stage of Ennis' cognition, after FC-
1. after FC he was certainly thinking about Jack, his words during FC, his infidelity and the anger that Jack had shown for the first time.
2.Next stage is after the phone call with Lureen when he found out how brokeback mountain was Jack's favorite place up to a point that he wanted to be buried there - of course that Ennis knew that he's the reason for Jack's loving Brokeback so much!
3. And third stage is after finding the shirts - then everything was pretty much clear. Ennis knew that what they had was Love, and this is going to be his open wound for the rest of his lonely life!
