A big misconception about happiness is that it's something to attain, and keep, forever. Science encourages people to reject that mindset and instead view happiness as multi-faceted.
It's possible to have multiple kinds of happiness that contradict each other, such as when you need to turn down dinner invitations because you've committed yourself to working on a new book, or some other long-term goal.
In order to maximize happiness, humans seem to need to know what the bad moments look like — suffering is something to practice, scientists have found.