Watching Elon Musk at work is an exercise in controlling your urge to buy a man a drink. Make that several drinks. Musk is 36 years old, wicked smart, worth several hundred million dollars, and built like a tight end--thickset through the middle and well over 6 feet tall. Yet he never looks quite comfortable. Sitting in front of the oversize computer screen on his desk, he rolls back and forth in his chair, slouches and unslouches, rubs his temples, raps his fingers, and plays with his wedding ring. When he sighs, which he does frequently, his chest heaves, and his eyes widen, like someone confronted with news of his own death. He generally speaks in complete, precise sentences, rarely telling a joke or even cracking a smile.