First, 'doing' Law is more than cramming cases and statutes.
Acquiring the skills of thinking like a lawyer comes with practice, lots of practice. Just as children take years to acquire the skills of communicating in their mother tongue — learning from their parents and others, not just the vocabulary but also the grammar, the intonation, the subtleties, the structures of the language — the same is true for learning law. Robots can be taught the basics but law students develop an affinity for the subject by being exposed to different writers, critics, disciplines, arguments. On a Law degree, you read the primary sources and make up your own mind. For instance, was it really right to prosecute a fifteen year old for his completely consensual relationship with another fifteen year old, but not to prosecute her? Developing these critical skills takes time, more time than is available in a one-year conversion course.