Dr. Carl Hart

Professor of Psychology & Chair of Department of Psychology at Columbia University

Robert Reich

Economic Analyst, CNBC Contributor, Professor, Author, Advisor to Presidents & Former Secretary of Labor

Capitol Steps

Nationally Acclaimed Political Satire Troupe

Andy Borowitz

New York Times Best-Selling Author and Comedian; Creator of the Borowitz Report

Stephen Shapiro

Innovation Consultant & Bestselling Author of "Personality Poker" and "Best Practices Are Stupid"

Dolvett Quince

Fitness Guru & Trainer from "The Biggest Loser"

Lisa Myers

Emmy Award-Winning Former Senior Investigative Correspondent for NBC News

Bill Bryson

Best-Selling Author Known for "A Short History of Nearly Everything" & "A Walk in the Woods"

Dan O'Brien

Olympic Gold Medalist & Decathlon Champion

Steven Crowder

Conservative Commentator, Comedian & Former Fox News Contributor

Ellie Kemper

Actress, Comedian, & Writer Best Known for Her Roles in "The Office" & "Unbreakable Kimmy Schmidt"

Nick Offerman

Actor, Writer & Carpenter; Best Known for "Parks and Recreation"

Jill Abramson

Former Executive Editor of The New York Times

Vilayanur Ramachandran

Neuroscientist; Director of the Center for Brain & Cognition, University of California, San Diego

Philip Zimbardo

Psychologist Known for the Notorious '1971 Stanford Prison Experiment;' Researcher of the Psychology of Heroism, Evilness and Time

Lance Gross

Actor, Model & Photographer; Best Known for "House of Payne"

Dr. Travis Stork

Bestselling Author, Emergency Medicine Physician & TV Personality Known for "The Doctors"

Thomas Middleditch

Actor, Voice Actor, Comedian, Screenwriter Known for "Silicon Valley"

Lou Waters

Aging Expert, Journalist & Former CNN Media Personality; Anchor of "Coming of Age"

Where Are They Now: Lou Waters

Daria Musk

Singer, Songwriter, and Google+ interactive Concert Innovator