It is fairly common for people to put up a protest in response to hearing about the law of attraction and how it works. This naturally results in a person believing that they can think in any way they please and still be able to manifest their desires. This type of revolt has many different degrees too in that it can still affect you even once you have a thorough understanding of how your thoughts define your reality.
In other words, you may find yourself wanting something to become a part of your reality, but you may not be entirely willing to think in the way you must in order for it to happen. Naturally, due to the underlying structure of the Universe being vibrational in nature, this is impossible since in order for your reality to match a certain state, so too must your thoughts change to match that state to make their energy values equal to one another.
Therefore, in order for your desires to manifest, your thoughts must perfectly match their energy value in the form of thoughts of your desires being a reality at present. The more alike are your thoughts and their corresponding emotions to the ones you would be experiencing were your desires a reality right now, the more alike must your energy value then be to the one you would maintain were your desires to manifest.
The most striking instance of this effect would be immortality. In order to be immortal, you must think thoughts that match immortality. There is no middle ground here though, because if you think thoughts of mortality, you are then experiencing mortality which is not immortality. Even so, the greater is the degree of positivity you are experiencing, the more alike is your energy value to immortality. Thus, if you sincerely want to manifest something, make sure your every thought matches the desired state of reality you wish to experience more extensively, because your desire is only manifesting whenever your energy value perfectly matches it.