Be set in your ways
Definition 1 of 1
Pro Tip 1/3Age Connotation
Often used for older people who are less likely to change their habits. 
My grandma is set in her ways and prefers to write letters by hand instead of emailing.
Pro Tip 2/3Resistance to Tech
Commonly applies to reluctance in adopting new technologies. 
Even though smartphones are common, he’s set in his ways and only uses a landline.
Pro Tip 3/3Cultural Resistance
May express aversion to different cultures or new social norms. 
They're set in their ways and have difficulty accepting new cultural customs.