The worst phrase by the expert is: You don't know what information you don't get.
You have no idea how often I stared at someone thinking: "Do you fucking asshole of an ultra shmock want to share the full picture or keep calling me an idiot?"
Because: There are known knowns. Then there are knwon unknowns and finally unknown unknowns. The latter, if I may add, can be concluded by estimating the prior, roughly.
If you have no idea what I am talking about, a unknown known is what you forgot. I hope that helps. Moron.