Do you see the difference in the quote above? The great minds have purposes, while the others have wishes. I actually believe that what the author tries to tell us all is that the difference isn't really about whether you have a great mind or not, but what actually decides whether you have a great mind or not, is whether you have a purpose, or if you are only wishing.
What is the difference? If you have a purpose, then you have a reason to wake up and you have something that you are working to acquire and accomplish.
If you only wish for something, then you might write it on a list, but you do not make a plan or do a lot to receive it.
For example, if you write a wish list to Santa Claus, then you might write down that you want a Nintendo Switch, a Playstation, or a new video card for your computer. But, that is still just a wish list.
It suddenly turns into a purpose when you not only write it on a list, but you create a plan and work hard to find a way to actually get hold of what you wrote on your list.
So, how can you leap from being a wisher to a purpose-driven person?