My biggest fear is being put under for surgery and waking up in the middle of the surgery without being able to move or scream or show any indication that you can feel every single little cut that they are making to you.
I think I have seen way too many Oprah and Dr. Phil shows that show these messed up individuals who were traumatized for life because of this very thing happening to them.
So when I am a surgeon one day, I will put the little white thing on one's head to make sure that there is no brain activity throughout the surgery.