boggle (one's)/the mind
To thoroughly overwhelm, confuse, or surprise one. The show of support from everyone just boggled my mind. The plot of that move totally boggled my mind—did you understand it?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
boggle someone's mind
to confuse someone; to overwhelm someone; to blow someone's mind. The immense size of the house boggles my mind. She said that his arrogance boggled her mind.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.