The story
A form of the now-obsolete An old dog will learn no tricks.
Etymology from Wiktionary, CC BY-SA 4.0.
you can't teach an old dog new tricks
Today it means: It is impossible to change people's habits, traits, or mindset. Full definition →
Today it means: It is impossible to change people's habits, traits, or mindset. Full definition →
A form of the now-obsolete An old dog will learn no tricks.
Etymology from Wiktionary, CC BY-SA 4.0.