People sometimes talk about it in terms of exams in the sense that they'd achieve a first overall if that exam was 'it', or that it brings their average up etc. - but strictly speaking you can only achieve first class (or any other) honours for the degree as a whole. It's commonly (but not necessarily) >70% overall. Equivalent to achieving some high GPA range.
I have always known it as "C's get degrees" but that's sort of a crass expression, not really the equivalent of the quote which is presented as "life advice" for the enrichment of those that receive it.
"C's get degrees": The bare minimum to get the credential is the optimal use of resources.
"You want either a first or a fourth. There is no value in anything between.": Either excel at school to maximize your achievement or don't worry about your grades and simply pursue whatever comes your way from the opportunity to be there to enrich your life.
Amusingly along those lines, I once had a prof in my Ph.D. program tell me that if I was getting all A's in my coursework, I was doing it wrong. (I.e., not spending enough time on research.)
This is pretty common at other places - my PhD advisor was exasperated that a polymer chemist would get an A in Physical Chemistry II, when I had a national lab collaboration to work on, a fellowship to write, and a first-author paper to get out the door.
In retrospect? Yeah, I probably should have taken a B and finished relevant things faster. I have almost zero use for my understanding of the mathematic accounting of the particle-in-a-box.
Of course in grad school a C is a failure, so the wiggle room is slightly less generous.
In high school maybe. All my stem classes in college were graded on a curve. First exam freshman year was physics. I walked out thinking I failed. There were questions I did not answer. Later that night they posted raw scores. Mine was 48 pts out of 100.
I was ready to withdraw and reconsider engineering as a major.
Later still they posted the cut offs. 40 was the cutoff for an A. Avg was 36 and the cutoff for a B. My 48 was the 4th highest score.
