A little learning is a dangerous thing
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;It is often stated as: "A little knowledge is a dangerous thing"
Drink deep, or taste not the Pierian Spring:
There shallow Draughts intoxicate the Brain,
And drinking largely sobers us again.
See also: Better untaught than ill taught
If you say "a little learning is a dangerous thing" you mean something like