I don't get a chance to write much C, but it's definitely an intriguing language. When I'm writing C++ I tend to focus all of my efforts on OOP paradigms and do very little of the nitty-gritty, low level memory stuff. I don't have to tell anyone the advantages of OOP, but when you look at some of things you can do in C, you start to realize there is so much taken for granted at the lowest levels. There are also some oddities that will surprise you.

If you're just getting started with C, I highly recommend this video series from Standford: