Intelligence undermines hard work all too often. I wasted years of my life coasting, as coming top of the class in everything was easy, and only actually started applying myself after university, when it rapidly became clear that intelligence alone doesn't cut it.

You've gotta be smart, you've gotta be prepared to work insane and thankless hours, you've gotta be tough as nails to hear but ignore the naysayers, you've gotta be willing to lose everything, and above all, you've gotta believe in yourself.

Only when you put all of those together (with krazy glue, of course), only when you are leading yourself, can you hope to lead others.