This week on Know It All, Greg Brown and Mitch Moffit from AsapSCIENCE look at the difference between like, love and lust. Inspired by the rom com Your Place or Mine starring Reese Witherspoon and Ashton Kutcher, they look deeper at the brain chemistry that cause us to feel love, why it can be so addictive, and just how long the honeymoon period lasts.