Well, it is possible. I think it can depend on certain factors: in the Facebook example it can be that she uses a different notion of time (different from yours). She could have been a fervent visitor of Facebook (and checking what everybody writes and likes), until one day she decides she no longer trusts the Zuck, and quits checking in, or quits all together (hence “I don’t do Facebook”) The salt thing: I always used to put plenty salt in the food I prepared, and ate all kinds of savory snacks, until I was urged to quit consuming salt as much as possible. From that day on I almost loathe salt; when I take one crisp/potato chip, my face contracts like a baby who’s biting a lemon. Maybe you just meet her every time she changed a certain behavior or habit?