New concepts, yes, but I think anyone who has spent any significant time programming in C++ will immediately recognize the problems that they are solving and how the solution works. That significantly eases the learning curve in my opinion.
Basically I get the high level abstractions and package management that I expect from Python, while inheriting a set of tools that help finally realize some of the high performance, zero-copy idealism of C++ (slices, lifetimes).
That's why is better to learn Rust coming from a C++ background.
(And in my experience this mental model can also be of value even in languages were memory management is handled by the language runtime)