I was asked to act when I couldn't act. I was asked to sing 'Funny Face' when I couldn't sing, and dance with Fred Astaire when I couldn't dance. Do things that you don't know you can't do.
Lisp is worth learning for the profound enlightenment experience you will have when you finally get it; that experience will make you a better programmer for the rest of your days, even if you never actually use Lisp itself a lot.