I am a very beginner programmer and I was totally "lost" inside the jungle of languages for about 6 months, knowing "nothing about how/where to start from zero".
Then I found this nice site (this is not an ad, just my experience) which teachs programming languages from the very beginning in a funny and not-tedious way. Well, they begin with this first language:
Because C is the mother of mostly all popular languages that came after C. Sometimes C is the only mother, sometimes languages have many fathers, but whatever... I mean, almost every language, including modern ones, like JAVA, behaves to C++, which came directly from C.
With pre(or post?) C -knowledge, I can tell you by my experience, you can really learn fast and easier other languages. Also you now know what is going on the underground when you run some "nice" command on a higher level language(like a GC), and this will probably make you a better programmer in almost all languages, with a better view of the entire process, since knowledge doesn't hurts.
Another advantage is you can control with more details things like, for example, a garbage colection, (more work, but maybe you need this), and you are really, really at bare metal. I guess more than this only with assembly, but this is nuts!
Ferraris doesn't have ABS.
C is one of the most fast languages in run time. (there is why is common to see C in drivers and anything that need speed = PERFORMANCE X [Some more job to write code].)
Pure C is still used, and run anywhere. It's just a matter of choice. You just have more options today, and thanks C for this. =P
I usually thanks C for anything new that I learn in another languages.