Barack Obama always wears the same thing: only gray or blue suits.
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. 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.
Using your decision-making energy optimally is a great habit. The above behavior is just a manifestation of this habit
Other famous people who have this habit: Mark Zuckerberg, Steve Jobs, Albert Einstein.2