Do you not think you are ready? Not enough practice, wrong gear choices, routes not planned, unfamiliar with the route not enough time. Yep you and I are the only ones! I have never been really ready.
I have done this a couple of times and I still am nervous about it. I love getting the jitter bugs just thinking about what I am going to be doing. I would quit if not for this thrill. For some reason I do not think I am alone.