My reasoning why is due to the fact that I believe (at least for me) the most beneficial way to activate LOA is the belief in oneself (myself). Am I making sense here?
Having a healthy relationship with your own spirit, your mind, is so key because it aids in the more difficult aspects of LOA such as detachment and letting go. You can apply pretending until you believe, but as Ginny says, it only works for people who are suited for it. I myself can say it never worked for me because I felt dishonest with myself. While the Universe may not see dishonesty as us humans do, humans have their definition of it.
As humans, we have our senses, each person has a sense that is stronger than another, therefore we react differently. Someone who believes that happiness is physically tangible will have different views as someone who believes that happiness is spiritual. None of it is wrong, but in the subject of LOA, both would initially approach it differently. Due to these differences, both people would give off different energy, not because they want to, but with what's already ingrained in them (subconscious belief).