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.
"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.