Break the Root(ine) of Our Downfall

Most of us know the feeling: the new car we guard from every scratch, the mitzvah that once lit us up, the marriage that slowly slides into routine. Rashi says Aharon could not enter the Kodesh HaKodashim whenever he wished, so that he would not grow used to it. If the holiest man in the holiest place was at risk, where does that leave the rest of us?Rav Chaim Shmulevitz calls habit the quiet enemy of avodas Hashem and of every close relationship. A woman in Chazal tells a sage why the man she grew up with married someone else. What keeps a fire from going out?