With that cheerful exhortation in mind and since I was only booked for a couple days, I decided why stress out? If they don't like your work, they can bring someone else in for the next time.
My "devil may care" attitude regarding the outcome of future employment freed me up to relax a bit and I actually somewhat enjoyed the remainder of that day and the next. Not only did I not hate it, but I felt like I learned and became more skilled passing some of the two year training markers.
Unfortunately there is a lot of pressure placed on people to perform when they are trying to learn or achieve something. That's why children can become masters at things because they are simply playing and not thinking about the ramifications of success or failure.
Nothing is really so serious that it needs to wreck your life with stress. Try - either you'll get it down or you won't. Unless you have ridiculous expectations for your life then you will find your way and for some people the "way" is constantly finding the way as they become an amalgam of experiences and skills. "Start where you are. Use what you have. Do what you can". I'm chanting that right now.