First of all, it needs to be clarified that Socrates never said this sentence. As we all know, 95% of Socrates we know today comes from Plato's account. Socrates in Plato's account is the closest to this meaning, which comes from the Pleadings. The original intention of the original words is not that Socrates knows nothing, but that Socrates is a little smarter than those who really know nothing. Why? Because these people who think they know a lot have no exact "knowledge" at all, but only a bunch of "opinions". And I Socrates at least know that I don't have exact knowledge. Because of this, I am the smartest person in Athens.

according to Socrates, knowledge is associated with what really exists, that is, "being". Ignorance is naturally associated with non-existence and "nothing". The question of existence-non-existence and existence-non-existence cannot be expanded here. For those things that do not exist completely, do not exist at all, but are somewhere in between, the grasp and understanding of this part is opinions. For example, many people know how to appreciate beautiful paintings and beautiful music, so they think they know "beauty". But Socrates thinks this is just an opinion, not knowledge. Knowledge is the mastery of pure "beauty"-obviously, all people, mortals, can grasp only the concrete things of beauty, not beauty itself.

therefore, the simplified version of Socrates' famous saying "I know that I know nothing" itself violates Socrates' theory. Because what you know must be something that exists, not something that doesn't exist. It is meaningless and impossible to say know nothing.

Aside from philosophical arguments, as far as our daily experience is concerned, Socrates' famous words just keep us modest from time to time, so as to prevent ourselves from treating ignorance as knowledge and half-knowledge as knowledge.