I love what this says about Zuck. It takes real conviction to make decisions this big and this fast. Most people would feel the need to build a faux consensus of people around them for moral support. Same thing that let him say no to his own $1 billion acquisition offer I suppose.
He's 26. He went straight from Harvard to Facebook. He still effectively controls Facebook. And he's a billionaire. I don't think he really can take a risk, in the sense that a normal person would think of a risk. As long as he doesn't do something blatantly stupid like run in front of a bus, he's probably set for the rest of his life. Instagram deal not approved, or approved but doesn't "work out"? Shrug. Still a billionaire. And I'm sure he's taken a lot off the table already so even if Facebook's value plummets, he should still be gold.