C gives you a behind the scenes look at most abstractions you use in terms of data structures. You create and destroy things such as lists, trees and such. You manage your memory manually and that let's you appreciate the work people put by making languages that do those things for you but you also learn a lot in terms of abstraction.
There are surely languages you use or will use which implementations are in C ( Python for example )
I think it's somewhat similar to a question with JVM languages.
Do you have to learn a bit of Java to get a deeper understanding of Scala of Clojure?
Do you have to learn a bit of Latin to express yourself in English or Italian a bit more fluently?