"Wouldn't you rather spend it with Mr. Stark? You don't have to go out of you way, Bruce. I might be...safer...at the Institute. I'm not sure what SHIELD will do when they realize I'm not going to be able to turn this off." That it will always be a struggle.

That there's a monster lurking underneath. He's not like you. He can't just run. It's not who he is. He's too sloppy, too moral. He'll be caught in no time, no matter how clever he truly is.