change of heart
noun pl. changes of heartThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A reversal of one's opinion, attitude, or feelings.
change of heart - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Altered feelings or attitude, as in Paul didn't like his new job, but a raise prompted a change of heart and he became quite enthusiastic. [Early 1800s]