JB
The teachers are charlatans. Every lesson can only be learned by the individual through life experience. Every child gets burned at least once, because no matter how patient or understanding their parent is, that kid is going to touch the oven door once in his life.

Jesus taught in parables, so that life experience could be expanded to cover new subjects, thus allowing Jesus to actually teach. Everyone else is repeating what they read or recalling events in their lives which could just as easily happen to the students. There are no great secrets that can be answered by any secret society or coven or Cabal, guru etc. The best place to hide something is in plain sight. If you are hiding jewelry, put it in a potted plant or a flour pot and nobody will find it. If you look around, you might find a vast source of ancient wisdom hidden in plain sight.

What Jesus taught was not new either.

JB

That's partially true, what Jesus taught was as old as the earth, but Jesus plainly presented those lessons to the people for the first time. The lessons taught by Jesus can be found in the Old Testament as well.