Researchers at the San Francisco State University in the US found that a "balanced time perspective" involving looking fondly on the past, enjoying the present and having goals to strive for in the future can make people feel more happy.
Having this sort of positive and balanced outlook can make people feel more vital, more grateful, and more satisfied with their lives, said Ryan Howell, who led the research.
"If you are too extreme or rely too much on any one of these perspectives, it becomes detrimental, and you can get into very destructive types of behaviours," Howell said.
"It is best to be balanced in your time perspectives," he was quoted as saying by LiveScience.
While it may seem obvious that people who have a positive attitude about their past, enjoy the present, and focus on goals for the future would be the happiest, Howell said that a sense of well-being depends on the balance between these elements.
"If you are really dominant in one type of perspective, you are very limited in certain situations," he added. "To deal well when you walk into any situation, you need to have cognitive flexibility. That is probably why people with a balanced time perspective are happiest."
It can be fine to have fond memories of childhood, for instance, but spending too much time remembering the past can keep you from enjoying the present.