Stress
Ever play the game Operation as a kid? Stressful, right? And if you screwed that up, all you'd have to do is listen to a brief mechanical buzzing and maybe lose bragging rights to your little sister. Playing that game in the real world? You make one little slip and you could lose...your little sister. Yeah—we would say that's stressful.
You may also have noticed that it's easier to be stressed out when you're not going on a lot of sleep. As a surgeon, you're not exactly sleeping in and rolling over to the OR whenever you feel like it. So your anxious state may be exacerbated by your tired one. Take our advice—be able to completely separate emotion from your job and be able to function fully on three hours of sleep. We didn't say it was easy advice to follow.