I only mentioned that he wasn't a rookie because it seemed to me that a lack of confidence from a former #1 draft pick is something they would only experience as a rookie, unless...
Typically, a 1st round draft pick either picks it up immediately and becomes productive or it takes a year. You build the core of your team from mostly premium picks.
I'm concerned because, in the past 11 seasons, only one of the Cowboys 1st round picks failed to become a Pro Bowler during their rookie contract. We all know who he was and what became of him.
in fact, only two of the Cowboy's past 10 1st round picks failed to make a Pro Bowl by the end of their 2nd season. Michael Jenkins did eventually make a Pro Bowl in his 4th season and the other guy was Taco Charlton.
Then again, there is that rare occasion where, just when it seems a player is not going to get it, something inside of him clicks, and he turns it completely around. Perhaps Zimmer will be that catalyst. I'm just not as encouraged nor optimistic as you, I wish I was.