be set in your ways
be set in (one's) ways
To be habituated to one's routine or usual behavior, often to the point of being unwilling to change any aspect of it. Grandma will never retire—she's been a teacher for 50 years and is totally set in her ways. You'll never convince him to change, he's too set in his ways now.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
be ˌset in your ˈwaysbe unable or unwilling to change your behaviour, habits or ideas, usually because you are old: He’s too set in his ways now to think about a career change.
Farlex Partner Idioms Dictionary © Farlex 2017