Once bitten, twice shy
An injury makes a person wary of its cause.
The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Idioms and Phrases with once bitten, twice shy
once bitten, twice shy
Once hurt, one is doubly cautious in the future, as in He was two days late last time, so she's not hiring him again—once bitten, twice shy. This seemingly old observation, presumably alluding to an animal biting someone, was first recorded in 1894.
The American Heritage® Idioms Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.