<-- updated -->

Possible interpretation: It may be safer not to learn something at all than to half-learn it.

Note: This well known proverb originates from Alexander Pope's "An Essay on Criticism":

A little Learning is a dang'rous Thing;
Drink deep, or taste not the Pierian Spring:
There shallow Draughts intoxicate the Brain,
And drinking largely sobers us again.

It is often stated as: "A little knowledge is a dangerous thing"