This concept can be applied in all fields of human existence. We are made of atoms but how many of us have seen an atom? We know this because "someone" told us about it. Are you so sure you have a beating heart? Have you ever seen it? Who says you do not have a Swiss steel mechanism that pulsates rhythmically in the middle of your chest? You trusted an anatomist and then his successors. But if the anatomist has never seen planet Earth with his eyes, the astronaut has never (probably) seen a heart beat live.
The human being, despite being (perhaps) the most intelligent inhabitant of the planet, is not able to know everything. It is practically impossible to find one of us with such a huge culture that he can define himself as an expert in any field of human knowledge. The man then thought well to "divide the tasks": a good social animal has created fields of utility and has entrusted them to every member of the community. There is one who knows how to get food, the other who knows how to build shelters for the night, the one that heals the wounds and the other who knows how to orient himself in the forest at night.
Everyone is useful to the group and in return benefits from the benefits of the same group (all for one and one for all). But man is mortal, so he soon understood that the knowledge had to be transmitted, from father to son and from one member of the group to another. Society could never do without one's experience and wisdom.
If the baker had failed, no one could have replaced him and even the hunter, the seamstress or the warrior would have suffered, he would have died and the group would soon be extinct.
Then they began to pass on the arts and crafts, then knowledge and wisdom.
Each generation would have refined the arts, learned from mistakes, selected the good and the bad until reaching an almost perfection that made man an unbeatable and practically unrivaled being. We dominate on Earth because we have been able (thanks to our physical qualities) to become a society with individuals interdependent with each other but absolutely different from one another.
All this until today.