be none the wiser

Từ điển Oxford Advanced Learner 8th

be none the ˈwiser | not be any the ˈwiser idiom
1. to not understand sth, even after it has been explained to you
•I've read the instructions, but I'm still none the wiser.
2. to not know or find out about sth bad that sb has done
•If you put the money back, no one will be any the wiser.
Main entry: ↑wise_idiom