I read this article by Paul Graham, it's such a delight. In his article he explains, how being like a kid having a unfearful, no direction, no consequence confidence as a great way to achieve great things because as adults we are much mature to have such kind of confidence.
But what is the root cause of fear of that failure. Knowledge and what we call wisdom, does that mean having more knowledge and being logical makes us less successful it makes no sense. This point in a way coincides with the book I'm reading "Blink by Malcolm Gladwell", which is about intuitive nature of subconscious and having more information is not always good. In the book, the author explain how having more information supresses your intuitive subconscious from making snap decisions which are optimized over billions of years of evolution for net positive outcome i e survival.
When kids have a passionate project this inner voice is the one which is speaking to them into following their passion instead of the carefully laid path of school curriculam which definitely won't let them survive out in the world.
This inner voice of being authentic to yourself and following your inner voice is greatly advocated by Fredrich Neitzsche.