Dopamine biases individuals towards thinking about what they do not have, driving pursuit of external goals.

“dopamine biases us toward thinking about what we don't have, whereas serotonin and some of the related molecules like the endocannabinoids if you picked up on the word cannabinoid, yes it's like cannabis because cannabis attaches to endocannabinoids receptors and the endocannabinoids are receptors that and chemicals that the cannabinoids that you naturally make that are involved in things like forgetting.”