What can I learn from those who have already achieved my goal?

I have the goal of getting a very specific job within the next twenty years. I am thinking of looking at the paths of those who have/have had this job in the past in order to inform my action line to achieve this goal. Did they write a book? Did they teach? What other sectors did they work in? How public were there personas before they came into the position? BUT… I also know that the true magic comes from imagining something that hasn’t happened yet and going after it, so I don’t need to look at these people’s paths, I just need to focus on my own. I know I could do what I think best prepares me for what I want to do, but I also know that the traditional career advice is to look at the job description of the job you want and get the experience and skills it calls for. The position I want is not the kind that has a description, it is headhunted, so the best way to determine what experience and skills gets you there is by looking at that of those who have had the job before. What is the LCS philosophy approach on this?