Several months ago, Sarah told her best friend John she’s in love with him—but he doesn’t love her back. Now Sarah can’t get John out of her head, especially because they still talk all the time. How can Sarah move on from John? On this episode of How To!, we bring on Helen Fisher, a biological anthropologist and the author of Anatomy of Love, to help Sarah train her heart—and her brain—to fall out of love. The first thing Sarah needs to do, Helen says, is cut off contact with John. Every time she sees him, it reactivates her brain circuitry for romantic love. And as beautiful as their friendship may be, it’s holding Sarah back from finding her true love.  If you liked this episode, check out “How To Propose (to a Man).” Do you have a problem in your love life? Send us a note at howto@slate.com or leave us a voicemail at 646-495-4001 and we might have you on the show. Slate Plus members get bonus segments and ad-free podcast feeds. Sign up now. Learn more about your ad choices. Visit megaphone.fm/adchoices