There are no setbacks.
Emotional and creative development do not follow a straight line. What feels like a setback is only a variation.
Our schools train us to think in a straight line: 1 comes before 2, which comes before 3, and A + B = C. The more schooling we have, the more we absorb the message of linear thinking. This type of thinking affects not just what we learn but how we think of our lives and ourselves. We are taught to believe that if you study, or put in enough effort, you will pass the test and have success. This formula works quite well for many problems, especially those where there is an actual test or presentation.
Thinking in a non-linear way may not come naturally if you are classically educated. In fact, people who do not have a conventional education tend to have an easier time grasping the nature of emotional and creative progress, because unlike book-learning, life-learning involves, and indeed often requires, entering apparently 'blind alleys,' experiencing the sting of rejection, weathering feelings of failure, or enduring periods of time when it seems like all is lost.