Jung gewohnt, alt getan

Literally: Accustomed to it when young, doing it when old

Example: “Er räumt bis heute jeden Abend seinen Schreibtisch auf – jung gewohnt, alt getan.” — He still tidies his desk every evening: as the twig is bent, so grows the tree.

Origin: Four words, two contrasts: young and old, getting used to something and doing it. German makes the same point with little Hans: was Hänschen nicht lernt, lernt Hans nimmermehr, what little Hans doesn't learn, grown-up Hans never will.