I actually think that anyone with the true desire to pursue the course of action required. This will obviously exclude some people, for example those who cannot form that desire to start with.
I think it is the limiting beliefs like needing to qualify the exact quantity of a word that is the road block for many people. Also the need for exact precision that holds some back as well. Yes there are times for the use of exact language to ensure precision in what is taking place. But I have watched enough stories of people with nothing, from unexpected backgrounds do some rather amazing things.
Which leads me to believe that anyone with the true desire to achieve something can do it if they take the action which is needed to reach that desire.