Learning syntax is one thing, learning to write good code is another thing, and learning community best practices and advanced techniques is yet another thing.

Learning syntax is one thing, learning to write good code is another thing, and learning community best practices and advanced techniques is yet another thing. You can be a competent Java programmer without ever reading a book like "Effective Java", but reading that book will probably improve your skills. The same is true for PGSQL (or any other language). Sure, you can pick it up on your own, but mastery is achieved with experience and education.