Where did you learn a thorough knowledge of the Catholic church’s interpretation of the Bible?
That’s kind of a loaded question. It’s very specific to an individual. Rather than answer for myself, I’ll tell my impression of a 30 y/o relative.
She had mostly a public school education, and she didn’t spend much time in a state university doing a bible study anyplace.
I’d conclude from that one case that Bible knowledge can be very spotty or almost non-existent. To make matters worse, she attended a women’s group meeting where bible subjects were discussed. She was really at a loss, and mostly expressing personal opinions. And, this was despite my best efforts to encourage her along the way.
Some Jews, Protestants, and Catholics are fairly knowledgeable, but then most aren’t. There are a whole raft of reasons for this.
Not only is this a loaded question, it’s a trick question. There’s not an official commentary that would be a yardstick for knowing how knowledgeable any Catholic is. The Catechism of the Catholic Church is a large, but not exhaustive summary of Church teaching on the Bible. It’s hard to know what the Church has taught over the centuries on every aspect of the bible.
Having said all this, I think puzzleannie’s response is typical, that such knowledge is cumulative and ongoing, and depends on one’s personal history.
Maybe the OP should be narrowed down a bit. What’s the point?