What makes Perl interesting to me is the philosophy behind the language design. "Since Perl was designed (loosely speaking) by an occasional linguist, it was designed to work smoothly in the same ways that natural language works smoothly." (1)
The three mantras that I remember from my days writing Perl are: "tim-toady" (There's More Than One Way to Do It); "Easy things should be easy, while hard things should be hard;" and (borrowed from Voltaire) "don't let perfect be the enemy of the good."
Perl is messy, because language is a messy business. Perl is expressive, in part because it is messy. Perl is fun to write, and if you have the spare cycles it's worth your time to explore, purely for the mental calisthenics.