Don't expect the results to come automatically. It is possible to intellectually understand how to attain happiness, yet not put it into practice. In fact, many people might actually prefer to be comfortable and unhappy, rather than endure the discomfort of changing their habits. Just as learning any new skill requires effort, you have to be willing to invest serious effort to achieve real happiness. Happiness doesn't drain your energy.
Happy people are energetic and ambitious.
There's never enough time to do everything they want to do. If I want to be depressed, that's my own prerogative. A beautiful Sunday afternoon. You're at the park having a picnic with your friends. It's too hot for volleyball.