Instantaneous About Face

An unmade bed has never bothered me. At. All. Forty-four years off blissful indifference. Then wham! All of a sudden—literally overnight—I’ve become a fanatic about making my bed. I have no idea what happened. It wasn’t a conscious decision of any kind. I just looked at my bed one morning and decided to make it up. Then I did it again the next day. And the next. 
Have you ever experienced an instantaneous about face like that, whether a small habit or a significant lifestyle change?