No one is ever born with a developed brain. But everyone is born with potentially developed brain. Who eventually gets it developed (and often is called “smart”) depends on how much of a good luck one has.
In us, humans, most of the processes happening in our brain, happen without our knowledge about them (exactly like in all other animals). Unless we deliberately think about something, we are not aware of what our brain is working on. Deliberate thinking is an exclusively human practice (e.g. The Deliberate Thinking v. Digging a Trench & The Importance of Early Exposure to Thinking). As any human practice, it can be trained to different levels of proficiency. As every human practice, it has its own side-effects. One of such side-effects is ideas that come seemingly from nowhere. There are many stories about people who came up with some important or unusual idea in their sleep. There are books on the role of an insight in science or business.
The one that placed the first man on the Moon?
Future over-hyped technologies like “AI” with its various applications, augmented reality, controlled fusion, space travel, or else, also will not be able to give a significant advantage to one country over others (probably, for good). But there is one technology that can do that - the technology for unlocking human creativity en masse. This technology does not yet exist, but possible. And no country is working on it, just yet. The one that starts the first will have all the advantage.
China v. The U.S.: The Battle Of Strategic Thinking