What is the secret behing the secret.  Concentrating on receiving does not work everytime.

Love&Lightjavascript:emoticon(':smt017')

For this I will go into what the Secret means to me.

I don't know that it is a mystical power as much as sound life management.  The process is that you have to:

Know what you desire (set goals)
Affirm this regularly (set goals firmly in memory - even subconscious)
Act rightly as though you had achieved goals (put goals into action)
Recieve (achieve goal)

And be positive about it.

I don't know that the Law of Attraction is some mystical power, but I can see great positives in living that lifestyle, so mystical or not, its the way to go.

As for why it doesn't always work?  There are a lot of outside influences that can alter the outcome.

Yes, consider all the energies at work.  Thoughts are things and produce energies.  Everyone of us is thinking all the time.  All that energy.  Just how would my little thought manifest in this wonderful sea of thoughts?

Also to help in manifesting, you should also raise your vibes,as in become joyous and therefore it becomes better for you to manifest.

And also to fully focus on your manifestation, as read from a book, you should shun yourself away from the outer world eg: meditating for about 15 minutes to deliberately focus on your desires.

That which we concentrate upon, we will manifest.  It is the law.  

Consider...you are using the LOA and thinking what you want.  What is the first thing that happens?  You think of all the things you don't want around your heart's desires.  So now it has turned negative.  And negative energy is somehow stronger than the positive and that is what will manifest.