Great point. No matter how engrossing or important the work I'm doing is, I've never been able to push myself to work past midnight. Something biological tells

Great point. No matter how engrossing or important the work I'm doing is, I've never been able to push myself to work past midnight. Something biological tells me I am done, my brain turns to soup, and I know I've gone past the point of diminishing returns. I've never been able to fool myself into believing that there is any point in doing any more. I look at these guys pushing themselves beyond the point of physical, mental and emotion exhaustion, and I just wonder how they do it. I wonder what drives them go on.