Who said that it is a wise man who knows that he knows nothing?

Question

Seems to me it was an ancient Greek fellow but I don't recall.

Answer 1

I thought the saying was:

"A wise man doesn't just know what he knows, he knows what he doesn't know."

Answer 2

Socrates does seem as the first one but i think it was said in ancient India in sanskrit but i dont recall  where it was mentioned.

Answer 3

"The fool doth think he is wise, but the wise man knows himself to be a fool."

-William Shakespeare

  

“To know that you do not know is the best. To pretend to know when you do not know is a disease.”

-Lao-Tzu

"The only true wisdom is in knowing you know nothing."

-Socrates