As one of the two platoon leaders serving under Jocko Willink’s US Navy SEAL Team 3 Task Unit Bruiser, Leif Babin was a key reason why the unit became the most highly-decorated American special operations of the Iraq War.

But that didn’t mean he was exempt from making mistakes. One that stuck with him was an early mission during the 2006 Battle of Ramadi, he told Business Insider in an interview about his and Willink’s book “The Dichotomy of Leadership.” It’s a story and a lesson he and Willink pass on to business leaders in their leadership consulting firm, Echelon Front.

Babin and his SEALs were preparing to go out on patrol with some Marines in a very dangerous part of the city, and he knew that their patrol would last at least 24 hours.

“So I loaded up for World War III,” he said. He packed extra grenades, ammunition, food and water, radios and batteries, and “everything you could possibly imagine to try to cover all these contingencies, in the event that we got extended out there, in the event that we were about to be overrun by a larger enemy force.”

But all of this, of course, was extremely heavy, he said. “I could barely keep up with a patrol and I certainly couldn’t lead that patrol. And that actually put me a much more dangerous situation, because I tried to plan for every single contingency.”

From that point on, he kept his contingency planning much simpler. He recommends that, even in a situation that doesn’t involve life or death, a leader prepare for three or four contingencies for every major phase of an operation, but “not over-plan so I’m trying to plan for a hundred different contingencies and now no one knows what to do and the plan’s so complex that no one can follow it.”

Willink added that the main takeaway should be about efficiency. “We see businesses sometimes where they invest so much time and so much effort into their planning that they actually never make any progress on getting the project done, or at least they take away from their effort to actually execute the project,” he said. “You certainly have to plan but you can’t spend so much time doing your planning that you never get anything actually done. Find the balance there.”