shakestheground, you're right, the two threads do cover some of the same ground. Or at least maybe the "...rejected by men" thread answers my question? Anyway, I wouldn't mind having the threads merged if Katie would like that, as well, and if Katherine thinks they ought to be. I guess I didn't put the question in that thread, in part, because I wasn't sure that the "rejected by men" was the answer to my question. Or at least, I wasn't sure it was the entire answer.
I didn't word the question very well. Originally, I was thinking that Jack seems to compartmentalize his life, like he's got an Outer Jack who is the person that people expect or want him to be (and who can be different at different times, or with different people), and an Inner Jack. And I'm not sure we see the Inner Jack very often, even with Ennis -- yeah, Amanda, Jack really does pick his words carefully with Ennis, at least when Jack's saying something really important (the cow-and-calf-operation speech). And I was wondering whether if Jack was comfortable with having an Inner Jack that was hidden away (some people seem to be able to live very comfortably inhabiting various personas for the outside world, and staying very private about their inner self), or whether it was behavior that Jack had adopted in order to survive. (This is a little different, I think, than wanting to be able to live openly with Ennis. Or maybe it isn't. I'm not sure. I don't really understand Jack.)
And the sense of rejection might be part of it. Or maybe, the sense of rejection coupled with the desire for affection that Daniel describes -- Jack seems to want and need human contact. (I think the desire to be accepted and respected by his father, and maybe men like Aguirre and L. D. Newsome as well, is something different from the desire for affection from Ennis, or Jimbo or Randall... but they're all part of wanting to be liked or loved by other people.)
(And there was another interesting post about Jack-the-dreamer vs Jack-the-realist in here, and I think that might be part of it, too, and I wanted to respond but didn't have time yesterday. And it's gone now. But anyway, I know the post described the way Jack's window looked out on the only road that left his childhood home, and it seemed like that captured something about Jack, too. Only one road leaving home, and spending an entire childhood looking down there and dreaming. And being somebody who needs human contact, feeling very isolated with just his parents and the long horizons of the Wyoming plains. And being attracted to men, too. No wonder Jack wanted to get away, even if he also kept going back and telling his father that he was going to come back to stay.)