Dude. You read that as bitter because you want it to be bitter. You have this image of him all angry, sitting in his apartment stewing, and so that's how you interpret those 140 characters.
Look through his stream, and I see a pretty positive, upbeat guy who loves LSU and is looking forward to the NFL. He states he loves LSU multiple times. He's saying A&M looks good right now? Guess what - he's right.
The reality is, neither of us has any idea what he's thinking. But I'd bet that he's probably more at peace with what he's done than you are.
Having not seen his other tweets, because as I mentioned before I don't have a twitter account, perhaps I am missing some important context.
As for being at peace with our chosen directions in life, who knows. We both have done a lot of winning