Take the relatively short history of human physics development.
In the early stages, the content of physics was very limited, focusing only on initial thoughts about the motion of objects.
But by modern times, Galileo laid some foundations of classical mechanics through experimental studies of free-fall motion, and the amount of knowledge began to gradually increase.
Subsequently, Newton, building on the research of his predecessors, proposed the Newton's laws of motion and the Law of Universal Gravitation, establishing a complete system of classical mechanics.
During this period, the field of optics also saw initial development, such as the discovery of some basic principles of geometric optics.
The knowledge system of physics at this stage was relatively simple, and an individual could master the core knowledge of classical physics within a few years of systematic study, provided they received a good education.
