Harvard Magazine has a nice profile of surgeon and writer Atul Gawande that talks about, among other things, his constant state of flow.
Gawande had seen that part of the man's colon was ischemic -- dead and gangrenous -- and had ceased to move waste out of the body. He wasn't sure about the cause, but suspected a blood clot. One thing was clear: without immediate surgery, the colon would rupture.
After examining the patient, Gawande conferred with the resident in the corridor outside the man's room. He went through a familiar and well-practiced set of actions that he seemed to do without thinking: slipping his ring finger into his mouth to moisten it, working his wedding band off, unbuckling his watchband, threading it through the ring, and refastening it, all the while carrying on a conversation about stopping the patient's anti-clotting medication and getting a vascular surgeon to assist.