A GREAT PRINCIPLE (klal gadol) WAS STATED ABOUT SHABBAT
This principle: a person who forgets the fundamental laws of Shabbat is liable for only one sin-offering no matter how many violations.
The corollary: a person who knows the fundamental laws of Shabbat is liable for each a sin-offering for each Shabbat violated. A person who knows the specific Shabbat is Shabbat is liable for a sin-offering for each category of work violated.
Before getting to the specifics, though, the discussion is on the idea of a “great principle.” This is a term rarely used in the Mishnah. Other examples include tithes and 7th year produce.
But who is really the exemplar of the "great principle" here begins? Someone who never learned the laws of Shabbat – such as a child taken captive and brought up among Gentiles. In other words, the rabbis change the mishnah text from “one who forgets” to “one who never knew.”
Unlike the great principle of our civil society: Ignorance of the law is an excuse.