Self-actualization, in my opinion, is distinct from happiness. Happiness is a mood, while self-actualization is a state of being that cannot exist without a conceptualization of meaning outside oneself and satisfaction with the level of success one has enjoyed in interacting with that meaning. Happiness is something I've learned, in almost any situation, to simply "do," like brushing my teeth or tying my shoes. If I need to be happy for some reason, there are very few things that can prevent me from simply using body language, facial expressions, word choice, and other cues to produce the mood of happiness. (Of course, a massive personal tragedy can get in the way, but most anything else is not a roadblock.)

Self-actualization can't be synthesized or temporarily forced. The things I find most self-actualizing are not the things that necessarily produce the mood of happiness. To look on a completed piece of work and recall with pleasure the misery of producing it is self-actualizing. To walk away from it incomplete and have an ice cream sundae instead might produce happiness, but would never produce self-actualization. There is a level of exquisite satisfaction with the human experience in exhaustion, overwork, overgenerosity, and sometimes even failure.