Still, I'd love to get a job using Common Lisp, which I haven't really touched since I studied. Why can't I do that?
Because, in the words of Drew Crampsie (paraphrased): Lispers do not look for Lisp jobs. They look for work to do and do it in Lisp.
Edit: Also, I believe well-established Lisp companies (such as ITA or Clozure) usually look for experienced Lispers. If you studied it in school, what makes you a good candidate for these companies?