To further explore this topic, I would recommend reading the book Iconoclast[1]. It identifies "a lack of fear and mental laziness" as some of the key qualities rare extraordinary individuals possess. Having a child's mind and looking at things fresh was another way of putting it for me at the time I read it.

Reading PG's post, it immediately reminded me of the detailed analysis of this quality in the book.

[1] http://www.amazon.com/Iconoclast-Neuroscientist-Reveals-Thin...