Having a problem-solving mindset in addition to a powerful vision, is a great way to achieve greatness.
A lot of these greats made it a point to find and solve a problem in their society or world. Some of these problems were invisible to others not them. Some of the solutions they offered to these problems were outlandish and often mocked by their peers and superiors. The thing that made them great is that, they did not listen to these naysayers but rather aspired to solve the problems they identified.
Great post by the way. I learnt a lot from it