Intense behavior in a relationship, says McMillan, can sometimes be masking dependency, even if the person who's acting that way doesn't want to think so. "Why would you text a guy nineteen times because he failed to answer your first three texts?" she wrote. "Because you're not okay until you hear back from him. Why would you vandalize his property because he broke up with you? Because he has taken something from you that you don't want to live without: himself. Why would you still be fantasizing about a guy you broke up with months or years ago? Because deep down you're not sure you're ever going to find anyone better." McMillan says that if you've been doing incredibly intense (in a bad way) things in a relationship, you may want to spend some time with a therapist to figure out why you're doing so.

Bebeto Matthews/AP