1. be unaware of something or fail to understand something even after it has been explained
I did it without them noticing so they were none the wiser
The expression to be 'none the wiser', means to not be any more knowledgeable or informed about something despite trying to learn about it or understand it. You might say you are 'none the wiser' about something if you still do not understand something even after it has been explained to you. "My friend spent half an hour trying to explain quantum physics to me, but I left the conversation none the wiser!" This expression can also be used when there is an element of deception or hiding information from someone else. "My son hates vegetables, so I chopped them up very small and blended them into his spaghetti sauce and he is none the wiser".