Unless you're talking about a public library catering to homeless people and children, a "librarian" is typically an educated professional, usually with an advanced degree, who has enough subject matter expertise to efficiently help researchers find relevant materials.
Indeed! Librarians are often very highly educated, the couple I know have masters degrees. If you need something, no matter how obscure, you can ask a librarian, they will know how to get it for you.
I was disagreeing that public libraries cater to only the lowly forms of society (homeless and children) and don't require educated librarians. They do more than babysit and they employ such librarians. They also employ, for example, teenagers to stock shelves.
interestingly enough i know a few people with masters in library science - though, they studied how to organize and present information as opposed to holding a subject matter expertise (in this case agriculture)
