put ideas into someone's head
Also, put an idea in someone's head. Suggest something to someone, as in No, we're not moving—what put that idea in your head? [Mid-1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.