[JayNeely]

I wouldn't let a single requirement that you don't meet deter you from applying -- if you're a 90% match for a company's requirements list, and truly believe you'd be a good fit for the job, chances are you're a better candidate than many other people applying for literally everything that has a particular job title, regardless of their experience. It doesn't hurt to apply. Just make sure you're pursuing other opportunities as well.

Since you're a Stanford student, I'd guess Facebook actually comes to your campus for some recruiting events as well. Check with your career center to find out. Meeting one of their recruiters in person would be a good chance to ask questions about their requirements and how your experience might match.