Kiwi Chick has it right, but the fun comes when no one knows whether you have it or not. Not HR. Not some crappy test. Not an over inflated sense of ability. It seems the only way to tell is to get someone in to do it - and even then it's often hard to tell until towards the end of training when you can start testing at the required levels of traffic and complexity.
If anyone can reliably predict thos who've "got it" they could make a mint!