This episode is about sex drive in long term partnerships. Shambudram says we are taught through rom-coms or through the definition of what love is, that we want to keep and hold on to that passion. But many scientists will tell you that true love begins when that phases over and we move into companion love. We've evolved three distinctly different brain systems from baiting and reproduction. One is a sex drive, linked with testosterone in both men and women. The second is romantic love. And the third brain system is attachment, that sense of calm and security.