There's usually a moment in a trial, just before the first expert testifies, when the judge tells the jury how experts are different from other witnesses. Experts don't have percipient, first-hand knowledge of the facts. Instead, they possess education, training, or experience that permits them to share helpful opinions with the jury. Such an instruction sounds like build-up. But based on what we hear from jurors once a case is over, that build-up is usually a prelude to disappointment. Maybe it's like when somebody introduces you to new people and tells them how funny you are. Your new friends stare at you, awaiting a thunderous witticism. They expect Oscar Wilde -- or at least Adam Carolla. But you stammer and come up with zero chuckle-bait. You're not only not funny, you're guilty of false advertising.