Friend of mine once asked me this question. When it comes to myself, my educational background is engineering and from my own experience I know that if I fail I will do it again till I succeed.
This is similar to a maths exercises, if you are interested, want to learn and find a solution to a problem you will redo it again and again. Because you are aware of first, second, etc time failure.
This is completely opposite with people from artistic background. They are just too emotional and can not cope with a failure. After trying once they just give up as they have never solved a maths problem.
This is what you pay for success: time. You repeat everything again trying to find different approach from the other angle to a problem. This is how you build your stamina, knowledge and success.