I don't think so. It made Jack a better, more loving, and caring person.
Yes,to some extent...But when I said that Jack was who undergone the greatest change,far from the young sheep sheppard,I wasn't doing a qualitative comparison.I was referring to the fact that his way of being became more bitter,with less hopes and careless way of seeing life.In the sense you're referring to,of course the change was for better; almost always,difficulties make us grow as a person...
I didn't think that he became a worse person, but bitter and empty, in any case -not happy! For me it was difficult to watch.
Also, IMO (and I have to say that when it comes to Jack - I cease to be reasonable) he was always caring and loving person. What more could anyone possibly expect from him? I can not resent him anything, even the fact that he wasn't persistent enough with Ennis and failed to put a little more pressure on that stubborn head of Ennis. So, IMO the years of yearning, not getting what he wanted the most didn't change him to become a better or worse person, but he had lost a lot of his happiness, his enthusiasm and dreams. That's the change I'm talking about and for me it is a very sad part of the story. Love, the most beautiful thing that he ever felt, destroyed him in a way, cos the other part wasn't able to embrace him. Sad! :\'(