To use an old meme: "One does not simply learn C". Instead, one learns: 1. Everyday C syntax. It's not strictly required to learn every esoteric and historical

To use an old meme: "One does not simply learn C". Instead, one learns: 1. Everyday C syntax. It's not strictly required to learn every esoteric and historical thing about the language; if you go down that rabbit hole, you'll be down there for years. 2. How to properly structure and organize code and header files. It takes a little while to understand exactly what goes into a header file (and why), how to anticipate and avoid problems like cyclical include dependencies, etc. 3. Data structures and algorithms. While not a feature of the language itself, most projects are going to need non-trivial data structures (one example: hash map/table or alternative). Surprisingly, there are very few freely available implementations one can just import and use. By and large, every developer custom builds their own implementations. It should not be underestimated how much of a time sink this truly is. This aspect is trivialized by veterans, who have spent a decade or longer accumulating and tuning their own personal collection of reusable/tweakable snippets. 4. Compilers, linkers, and build tools. Thankfully the standard compiler options are good enough for nearly everyone, because the options are so numerous and complex that I'd bet even the developers of the compilers themselves get lost in that forest. 5. Finally, you're not doing much with C itself; rather, you're interfacing with everything your operating system provides. Most of your time is spent learning every aspect of POSIX (or equivalent) for your target architecture. This is quite straightforward (just time consuming) if you're targeting one architecture - say, Linux. The moment you want to support anything even remotely cross-platform (Linux, *BSD, macOS, Windows), you're essentially opening Pandora's box. Note that none of the above is really a criticism of C. There is simply more to using C than its syntax - and those other moving parts are where nearly all of one's time will be spent.