He'll be alright. He just thinks hanging out and getting shitfaced is a lot more fun than playing football. He'll do it for the rest of his life after he retires, living off he money he earned while doing pretty much the same thing as an active footballer. He'll think back on the years on the bench at some of Europe's top clubs as a fun time.
I think Bendtner feels he could be more than he is if he really, really put his mind to it, but it's not really worth it to him because he's already picking up a paycheck and gets to tag along in the national team while eating pizza and downing shots each weekend. He's just a typical average guy who happens to earn a lot of money and feels that fact absolves him from a lot of the social burdens normal people have to carry. And he's probably right.