From start to finish

You fail to start sometimes, just because you are scared if you will ever finish. That is why perhaps intellectual challenges are much harder at times, as compared to physical challenges as they do not have well defined goals, so you never really know if you have finished, you are never really sure that you are happy. I believe the ability to tune out everything else, when you are in pursuit of a special challenge must be a very useful trait to have. I wouldn't know much about it though, been there just once or twice !