I find it interesting, when famous quotes differ in meaning between different languages.

In German we have this cite of Platon:

Das höchste was ein Lehrer erwarten kann, ist Menschen an das zu erinnern, was sie immer schon wussten

I searched for the english equivalent, which states:

The highest form of knowledge is the knowledge that we already possess.

The direct translation of the german version would read:

The highest goal a teacher can hope to achieve is to remind people of what they have always known.

Both have a beautiful meaning, but they are not same at all. Perspective matters, it changes everything.
Now I wonder what the original in greek says.