C succeeded because it was the language of Unix, and it rode to success on Unix's success. C++ did indeed succeed because so many people knew C. Java has very little to do with C, except for the surface syntax, which makes it look as if it is similar to C, but its semantics are not like C at all.

You do not need to throw away everything you know to use Lisp. 90% of what you have spent your time on when you learn programming applies to Lisp just as well as any other language: variables, procedures, iteration, and on and on. At ITA, when we hire new hackers who don't know Lisp, we just give them a copy of Peter Seibel's excellent book "Practical Common Lisp", and they quickly pick it up.

Common Lisp, as it is used in real-world practice, isn't nearly as strange as many people think. (Yes, we have a job to do to explain that to the world.) It's not a new paradigm the way Prolog or Haskell are. You can get started, doing the kinds of things you do in Java, very quickly. Now, learning all the more-powerful stuff, like Lisp macros and how to effectively and tastefully use them, and more advanced object-oriented features of CLOS, does take some time to learn. But, then, learning all the useful stuff in the Java libraries takes time to learn, too, even if you're the best C programmer in the world.