I learned Perl as my first language as it was the language of choice in the first lab I joined. Over the years I've heard many criticisms, such as Perl code looks ugly and its motto "There's more than one way to do it" allows too much flexibility. I particularly like this description of Perl:
Perl would be Voodoo - An incomprehensible series of arcane incantations that involve the blood of goats and permanently corrupt your soul. Often used when your boss requires you to do an urgent task at 21:00 on friday night.