" In the basal forebrain there is something called the nucleus accumbens. It is a part of the brain’s reward system and has a significant role when it comes to motivation, pleasure, and reinforcement. Like all other vertebrates, we have this system because it is important that we feel pleasure when doing things like eating food and having sex, since these things are vital for our species’ survival. "

― Meik Wiking , The Little Book of Hygge: The Danish Way to Live Well