Benjamin Franklin used the following questions to lead discussions at his Junto meetings. Wikipedia link.

Author Tim Ferriss asked the following questions of over 130 world-class leaders for his 2017 book, “Tribe of Mentors: Short Live Advice from the Best in the World”.

Debbie Millman is "one of the most influential designers working today," as stated by Graphic Design USA. Ms. Millman has learned that winning a great job requires intentional, focused work. She challenges her students with the following questions as they prepare to find and win a great job.

Peter Drucker is often called the father of business management. Mr. Drucker viewed the ability to answer these five questions well as essential to business success. 

Distinguished American statesman and former Four-Star General Colin Powell served in significant roles under multiple U.S. Presidential administrations.  General Powell wrestled with decisions that had sweeping impact on the world stage and relied upon questions to decide a course of action. 

Author, strategist, and bookshop owner Ryan Holiday has distilled his list of worthy questions to engage over a lifetime down to his top 12ish, and then some more.

Speaker Tony Robbins has determined, “Our life experience is based on what we focus on.  The following questions are designed to cause you to experience more happiness, excitement, pride, gratitude, joy, commitment, and love every day of your life.  Remember, quality questions create a quality life.”

From “Awaken the Giant Within: How To Take Immediate Control of Your Mental, Emotional, Physical, and Financial Destiny!”

Kevin Kelly is Senior Maverick at Wired magazine. He co-founded Wired in 1993 and served as its Executive Editor until 1999. Kevin continues to be a thought leader and uses his creativity to invest in things that need to be made.

George Heilmeier was an American engineer, manager, and a pioneering contributor to liquid crystal displays (LCDs) technology. While Director at the Defense Advanced Resarch Projects Agency (DARPA), Heilmeier crafted a set of questions known as the "Heilmeier Catechism" to help Agency officials work through and evaluate proposed research projects.