One reason that challenge brings happiness is that it allows you to expand your self - definition. You become larger. Suddenly you can do yoga or make homemade beer or speak a decent amount of Spanish. Research shows that the more elements make up your identity, the less threatening it is when any one element is threatened.
Gretchen RubinSometimes, counter-intuitively, it's easier to make a major change than a minor change. When a habit is changing very gradually, we may lose interest, give way under stress, or dismiss the change as insignificant. There's an excitement and an energy that comes from a big transformation, and that helps to create a habit.
Gretchen RubinHappiness is a critical factor for work, and work is a critical factor for happiness. In one of those life-isn’t-fair results, it turns out that the happy out-perform the less happy.
Gretchen RubinVolunteering to help others is the right thing to do, and it also boosts personal happiness
Gretchen RubinHappiness can seem like an abstract, transcendent notion, but in fact, I found that getting enough sleep (very important!!), getting exercise, not letting myself get too hungry, not letting myself get too cold (I'm a person who is always cold), made a big difference. Partly because I felt happier, partly because feeling physically comfortable makes it easier to keep other difficult happiness-boosting resolutions like biting my tongue.
Gretchen Rubin