Is this issue related to psychology for traders? Lack of brains does not explain this echo in my head. http://ask.metafilter.com/88794/Lack-of-brains-does-not-explain-this-echo-in-my-head "I'd like to relate two stories from my father: 1. He had an infection in his left ear... he saw a doctor, the doctor checked his left ear, then went to check his right ear without removing the tip used in the infected ear. My father corrected him and that was that. 2. He went back a week later to his regular doctor, since the medication wasn't doing much. The doctor checked his right ear first, when my father told him it was his left ear he said "I know, but I like to see what the healthy one is like first." Also, since the right ear is healthy, there's no real risk of spreading the infection when he used the same tip on the left ear."