In our modern world, intelligence is typically measured by the IQ test. However, I think that their are many aspects to intelligence. There are, of course, certain individuals such as Elon Musk who seem to have a very high level of intelligence matched with imagination, resources, etc. to be able to achieve what he has done. I have no idea about other aspects of Elon Musk's life. However, there are many examples of seemingly very intelligent people throughout history, who in their own field were highly intelligent; however, in other areas, they knew nothing. Then there are the savants at the other end of the spectrum who appear to be very disabled mentally and physically, however, have an extraordinary level of intelligence and capability in a certain focused area. There are people who by all modern standards would appear to not be intelligent if they do not participate in our modern technology society; however, in their own territory of possibly survival or lifestyle they are extremely intelligent, while the modern technology supported person would be clueless.