Well, Operating Room is like this: you either fit in there with all your heart and soul or you simply do not belong there, complete clash of everything in your existance with the environment in the OR. The later situation was accurately predicted by my D. way back in HS and proven to be absolutely true for her during her surgery rotation. She does NOT have enxiety, she can stand on her feet physically, emotionally, intellectually. However, she is very sensitive to social interactions in any situation and realized that she does not belong in OR. That is exactly what she heard from the surgeons, one needs to love the surgery with all his heart or he is out. D. was out before she even tried and her OR rotation has proven that to be correct.
So, there is no reason to form cut in stone opinion before having this experience, unless you have wild imagination that has proven to be correct over and over. It is not your intelligence, it is not your physical condition, both of which are extremely important and could not be dimissed, but there is no much difference in this aspects form one med. student to another. It is your personality, and you simply may not belong in the OR. By the same token, as I pointed out before, you may simply not belong in the same room with the mentally ill, you may not have what it takes to deal with these type of deseases.
Again, focus on the aspects of your life that you need to deal with in the next 2 days and forget the rest. That will help you to perform your best, no matter what is the end goal. Just like a swimmer before a 30 sec. race, focusing on performing the best in the next 30 seconds. Keeping too much of long term prospective will bring enxiety, too much worry and simply will be an obstacle, not helpful at all.