Advertising Week, the industry's largest and most important gathering, celebrated its 10th anniversary in New York City Sept. 23-27. Those not in attendance missed out on some killer speakers, but just because you couldn’t be there in person doesn’t mean you have to forgo all the knowledge or fun that was shared.

Though several of the stellar speakers left their marks, three stood out to us in particular.  Whether they were discussing the need for competition or how good ideas can sometimes go wrong, these are three presentations you need to know about.

1. AARON GRIFFITHS, "YOU NEED AN ENEMY" 

On the final day of Advertising Week, Aaron Griffiths, chief creative officer of Arnold Worldwide, addressed something we sometimes forget in the advertising world—the enemy. If you think back on some of the greatest ad campaigns of all time, many of them had a chosen enemy to speak out against. Brands from Apple to Coca-Cola to Chipotle have all chosen enemies and used them successfully to launch campaigns positioning themselves against the enemy. 

2. VLADAS GRISKEVICIUS, "WHY CONSUMER IRRATIONALITY ISN'T SO IRRATIONAL"

Vladas Griskevicius is the McKnight Professor of Marketing and Psychology at the Carlson School of Management at the University of Minnesota, and at Advertising Week, he captured attendees and took them on a crazy mental journey. Griskevicius explained, using psychology research, why humans aren’t the rational beings we all perceive ourselves to be. When applied to consumer behavior, the results were fascinating. For example, women chose more provocative clothing when they were ovulating than when they weren’t, and 100% of students expect to be in the top 50% of their class. 

3. MATT MACDONALD, "MY BEST WORST IDEA" 

Joined by a few guests, JWT's chief creative officer, Matt MacDonald, discussed the center of the marketing world—ideas. MacDonald drew the audience in with his outlandish-but-relatable stories of ideas gone wrong. Included on the list was a brief ruined by Gilbert Gottfried, threatening phone calls from Russians to a creative team, and a client wanting a giraffe immediately.