[knotz]

It's a very fun language to begin with. Which is not unimportant if you want to keep being motivated after three decades being a programmer. Peter Norvig described 7 features which made Lisp different. Perl shares 6 of them. Important features like first-class functions, dynamic access to the symbol table, and automatic storage management. (source "High Order Perl" by MJ Dominus).

[nnq]

well, putting aside things "dynamic access to the symbol table" or run-time ast manipulation types of black magic, first class functions and "automatic storage management" are available in both Python, Ruby (...yeah, you need to twist your mind towards thinking in blocks/procs as first class functions, which annoys the hell outta me, but doesn't seem to be a problem for others) and most other "dynamic" languages.