While happiness is defined by the individual, I've always felt it foolish to declare that nothing can be learned from observing the happiness of others. Examining how to be happy is benefited from observing the patterns of others, and then taking only what you find useful.
Happiness is work in progress but everyone's process is different. The good news is that every day presents an opportunity to try something that can make you happier. Many people blame their circumstances, situations out of their control or other people for their own unhappiness.
Flow is when you are so consumed by a task or activity that you lose track of time, for instance, gardening, reading, or watching a movie. It's an optimal experience that can make you happy. Flow can be achieved in almost any activity that requires prolonged mental effort.
Seek out daily happy habits. Your brain will build up expectations of being happy and will rewire itself to seek more happy habits.