The only thing not mentioned is the variability of time scale. Sometimes the idea process can take years. For example, it took Bret Victor 10 years to find his ideas about UIs. ( https://vimeo.com/36579366 ) For truly world-changing ideas, 10 years is not uncommon. Steven Johnson explains this as a "slow hunch" in his TED talk --> "Where Good Ideas Come From" ( http://www.ted.com/talks/steven_johnson_where_good_ideas_com... )