Since the beginning, it's been obvious to many forms of life - not just humans - that there is a very large, very hot object in the sky. However it's only humans who have the intellectual ability to ask questions about what the Sun actually is.
Quite rightly, the Sun has been revered in culture as a force that maintains life and literally holds the planets together. And almost all the energy that powers civilisation is directly or indirectly sourced from the Sun.
