Do be careful with how deep or how quickly you dive into Lisp like functional languages.
Java never gave me any kind of nightmare, other than one time when a project's GUI decided that it all wanted to render in the upper left corner back in university, and a dozen professors and student's couldn't figure out why or how it happened.
But I do have nightmares from a time where I dug too deep into some ancient legacy code before I understood all the tools enough,.. and then someone misplaced a bracket... Or was the problem with parentheses?