Shabbat 68 - A "major" rule about Shabbat

The Sages stated a major rule about Shabbat: "Anyone who forgets the essence of Shabbat and consequently performs multiple labors and violates the Shabbat many times on multiple weeks - when he realizes that it was wrong, he has to bring only one sacrifice, collectively for all violations." Why is this so? Since some phrases of the Torah refer to single sacrifice, and some - to multiple ones, it is entirely logical to say that when there exists one root cause for all his violations - forgetting that there is a prohibition to do work on Shabbat in the Torah - that is the case where one sacrifice is brought.

What about someone who never even knew about Shabbat, like a child who was taken away in captivity when he was very young, or one who converts to Judaism on his own accord, without any Jews around to tell him about Shabbat? He did not forget, rather, he never knew! Still, Rav and Shmuel both say that he is responsible for one sacrifice for all his actions.

However, Rabbi Yochanan and Resh Lakish both say that the rule of one sacrifice refers only to one who knew about Shabbat and then forgot. One who never knew about it cannot be blamed for violations, and is thus free from any obligation to bring a sacrifice when he understands Shabbat.

Why is this rule called "major?" - Because there are more ways to violate Shabbat than, for example the sevenths year, or Sheviit - since its prohibitions refer only to plants still in the ground, whereas Shabbat laws refers also to things disconnected from the ground.

Art: Henry Farny - The Captive