Alternative opinion: the character trait not talked about is focus & drive. Obama is focused on doing his job the best way he thinks possible. So is Zuck. That means they don't have time for playing the "what should we eat tonight?" game with their SOs. And they simply don't care what they wear.

I'm aware of studies suggesting a set amount of decisions each day and that does make sense. However I don't think removing the choice of what you're wearing (and other menial decisions) measurably impacts your performance. It's a symptom of your ambition and drive for efficiency.

I recently went to a startup weekend. A group of young men started wearing the same shirts each day after reading the Zuck story. I think that is missing the point entirely.