Better to be ignorant of a matter than half know it. Publilius Syrus
To be ignorant of what occurred before you were born is to remain always a child. Cicero
Both angels and demons are ignorant of the future, yet they make predictions. The angels do so when God reveals the future to them and commands them to prophesy, and what they prophesy comes to pass. Demons also make predictions, but these are only guesses based on what they see from afar. John of Damascus
Have the courage to be ignorant of a great number of things, in order to avoid the calamity of being ignorant of everything. Sydney Smith
Being ignorant of law is no excuse. Polish Proverb
Bright enough in the dark, dull in time of day. [Learned in what is of no use, ignorant of everything at all available.]. Latin Proverb