Apathy – boredom when things are too easy or not meaningful; and
Anxiety – disquiet when things are too hard, unclear or caused by chronic dissatisfaction.

While happiness itself is sought for its own sake, every other goal—health, beauty, money, or power—is valued only because we expect that it will make us happy.
Happiness, in fact, is a condition that must be prepared for, cultivated, and defended privately by each person. People who learn to control inner experience will be able to determine the quality of their lives, which is as close as any of us can come to being happ

The best moments usually occur when a person’s body or mind is stretched to its limits in a voluntary effort to accomplish something difficult and worthwhile.

Finding this out included buzzing people on a pager at random points through a week. They were required to write down exactly what they were doing and the feelings that the activity produced. The discovery was that the best moments did not happen by chance, according to the whim of external events, but could reasonably be predicted to occur when a specific activity was undertaken. The activities described as being of highest value, which when undertaken banished worry or thoughts of other things, were dubbed “optimal experiences,” or simply “flow.”People in a state of flow feel that they are engaged in a creative unfolding of something larger; athletes call it “being in the zone,” mystics have described it as “ecstasy,” and artists term it “rapture.”

One of the key distinctions the author makes is between enjoyment and pleasure. While challenging tasks that require all our attention are enjoyed, mere pleasure does not have to engage us—it is passive. Television, drugs, and sleep can all be pleasurable, but involve little conscious will and therefore do not really assist our growth. The lesson of optimal experience is that we are genuinely happy when we are in control.

Mihaly Csikszentmihalyi (born 29 September 1934) is a Hungarian-American psychologist. He recognized and named the psychological concept of flow, a highly focused mental state conducive to productivity.

For success, like happiness, cannot be pursued; it must ensue…as the unintended side-effect of one’s personal dedication to a course greater than oneself.” — Viktor Frankl, Man’s Search for Meaning

Nakamura & Csikszentmihalyi (2001) suggested the optimal conditions for entering flow are the challenge-skills balance, clear goals and unambiguous feedback.

When in Flow, we are more productive. Studies have found that while in Flow, people can be 500% more productive.

5 neurochemicals in the brain at once is the most we can experience at any point. As a result, while in Flow, there is a significant increase in learning and memory.

Whilst the research is ongoing and individuals in flow show a range of brain waves, most people tend to experience a shift towards the Alpha/Theta borderline.

Human Brain Waves

"For success, like happiness, cannot be pursued; it must ensue…as the unintended side-effect of one’s personal dedication to a course greater than oneself.” - Viktor Frankl, Man’s Search for Meaning

“…being completely involved in an activity for its own sake. The ego falls away. Time flies. Every action, movement, and thought follows inevitably from the previous one, like playing jazz. Your whole being is involved, and you’re using your skills to the utmost.”

Studies on flow have demonstrated repeatedly that more than anything else, the quality of life depends on two factors: how we experience work, and our relations with other people.