In August, I posted a blog titled "Six Keys to Being Excellent at Anything." Over the subsequent three months it has become one of HBR's most widely read blogs ever. The notion that we can be excellent at anything prompted passionate debate. On the one hand, it's empowering and inspiring to believe that excellence is within our reach in any area to which we devote ourselves with sufficient diligence — something the researcher Anders Ericsson calls "deliberate practice."