I think there are multiple factors to Lisp's claim to fame, and other have covered a few of them. But one thing to also keep in mind is the historical context.

I think there are multiple factors to Lisp's claim to fame, and other have covered a few of them. But one thing to also keep in mind is the historical context. Lisp had features like garbage collection and much more of a "batteries included" standard library. It was a much higher level language, and more safe to use (memory safe, fewer incidence of off-by-one errors, etc.) compared to most other contemporary languages in the 70s and 80s (C for instance). You might still see a lot of Lisp advocacy aimed at wooing you away from those languages by touting the virtues of bignums/rationals, garbage collection, anonymous functions/closures, etc.. By the time the late 90s and 2000s rolled around pretty much of all of the popular languages had incorporated high-level features pioneered by lisp, and so now-a-days lisp doesn't probably seem quite as attractive to python or ruby or javascript or C# or Haskell users. Also, I think there may just be some personal preferences involved in different language choices. If you like C, and think it is a great language, then I'd say there is a lower probability that you'd like lisp, because they have a different philosophy about how programs could be built.