A dinner of roasted mammoth, berries, and leeks is served. Surrounded by your family and friends, you talk about the upcoming journey south as winter approaches and share survival strategies. Eventually, night closes in. The fire gives way to glowing embers. After another tiring yet satisfying day, you curl up in your corner in the cave and drift asleep. At what point would the concept of happiness enter your head? Were we happier a few millennia ago than we are in the present day?