Confirmed: Grandma's probably happier than you are

A book by Lewis Wolpert, professor emeritus of biology at University College London, sheds some light on the topic. Called You Are Looking Very Well, it argues that people are just “averagely happy” in the first third of their lives and that even that level of contentment declines by midlife.

“But then, from the mid-40s, people tend to become ever more cheerful and optimistic, perhaps reaching a maximum in their late 70s or 80s,” Wolpert told the Telegraph.

Several factors are at play, including maturity, diminished responsibilities and the ability to focus on the things that matter rather than chase elusive goals.