President Obama always wears the same thing. Which is part of his secret to getting so much done.

As he told Vanity Fair:

“You’ll see I wear only gray or blue suits,” [Obama] said. “I’m trying to pare down decisions. I don’t want to make decisions about what I’m eating or wearing. Because I have too many other decisions to make.”

This is because, the Commander in Chief explained, the act of making a decision erodes your ability to make later decisions. Psychologists call it decision fatigue: it’s why shopping for groceries can be so exhausting and judges give harsher rulings later in the day.

Managing decision fatigue calls for the high-value, low-effort systemization that entrepreneurs swear by. Whether or not our offices are oval, we need to find ways to reduce friction in our days. As Obama says:

“You need to focus your decision-making energy. You need to routinize yourself. You can’t be going through the day distracted by trivia.”

In 2012, Ryan Lizza had a big scoop for the New Yorker: hundreds of pages of White House memos. Woven together, the memos paint a picture of what the presidential workflow looks like–especially since this president prefers written advice to spoken. What’s most illuminating is how “decision memos” get delivered to his desk with three checkboxes at the bottom:

agree

disagree

let’s discuss

This is effective because, like always wearing the same suit, the checkboxes impose simplicity. While the decisions are obviously complex–how else do they end up at the desk of the president–creating three choices speeds up the feedback loop. Rather than submitting an essay test for each problem, the president can opt for multiple choice.

During their first presidential campaign, Barack and Michelle made a quizzical vow: “no new friends.” While we can’t peer into their decision-making process, that antisocial statement sounds like the kind of time-protecting strategy that Warren Buffett and Bill Gates always emphasize: you need to keep your calendar empty if you’re going to get anything significant done, like become president.