"Although, this concept will help you to evaluate things and get things done. It won't help you to achieve happiness. Nothing can."
Sounds just a liiiiiittle to depressing for me. While I admit that your not going to be %100 happy all of the time, do you not find that there are moments when your in bliss?
Also I found that economic concepts do a pretty good job predicting happiness for myself. They're not going to be perfect (obviously), but I would say that I'm reasonable happy with my life using the simple concept of diminishing returns and returns to scale.