Care-switch, n. - a switch in the male brain that, in a majority of men, malfunctions frequently. It controls the male's ability to give a fuck about people they love, predominantly females. In most cases, the male's switch will randomly flip to reverse, causing the male to become a distant asshat that can no longer shows signs of love, kindness, or caring towards special people in their lives. This unfortunate component of a male's brain causes distress to those the male used to care about. The only way to avoid care-switch related drama is to disassociate oneself from any kind of male contact, regardless of one's gender.
Girl: He broke my heart for no reason! He said he loved me thousands of times, but in just a few days he stopped caring about me completely! What's wrong with him?!
Girl 2: His care-switch just got flipped. Happens all the fuckin' time.