According to Moran Cerf, a neuroscientist at Northwestern University who has been studying decision-making for over a decade, the surest way to maximize happiness has nothing to do with experiences, material goods, or personal philosophy.

It's all about who you decide to spend time with. But "it's not just advice to choose your friends carefully," Cerf told Business Insider.

There are two premises that lead Cerf to believe personal company is the most important factor for long-term satisfaction.

The first is that decision-making is tiring. A great deal of research has found that humans have a limited amount of mental energy to devote to making choices. Picking our clothes, where to eat, what to eat when we get there, what music to listen to, whether it should actually be a podcast, and what to do in our free time all demand our brains to exert that energy on a daily basis... [read more]