go against the grain
To go contrary to someone's natural disposition: “Having to get up this early in the morning really goes against my grain.” This refers to the fact that someone who rubs his hand against the grain on a piece of lumber will get splinters.
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.