Thomas Tull, a American billionaire who runs Tulco–a holding company modeled in part after Berkshire Hathaway–shared in a recent interview some advice from Warren Buffet that reportedly “shifted his approach to investment decisions.” This according to a recent article in Yahoo Finance.

Recalling a two-hour meeting with Buffett in his Omaha office, Tull said the legendary investor shared a lesson Tull would “treasure for the rest of my life.” Specifically, when Tull was describing an approach he was contemplating for Tulco, noting what he was “trying to be smart about,” Buffett stopped him and said, “I gotta’ be honest, for years, Charlie [Munger] and I have always asked, ‘What’s the dumb thing we could do here?’ “

Buffett elaborated: “We don’t want to be in the clever pile. What could we do here that would be the dumb thing, and how do we avoid it?” Tull said the advice impacted the way he approached business situations at Tulco, a company that supports businesses through the application of artificial intelligence and other technical advances.  He praised the mental acuity of the 90-year-old Buffett, adding that he likely will never forget the conversation he had that day