In C for example, how does your knowledge & understanding & ability to use iostream/namespace std etc allow you to work with additional libraries, openGL for example? Sorry if this isn't worded the best, but I'm a noob when it comes to programming and stuff.

if you learn how to program with standard libraries, then how can you start working with additional libraries, if all of the functions/commands/operations etc, that you know of, aren'tpart of the new library.

example in C , if you start learning to program with the console application: cout, cin, etc. And you become proficient with that, how does it make any sense that you'd be able to go and work with a game design library, a library in which cout, cin, and all of those functions you know how to use don't exist?