This is actually very powerful concept. Whatever you believe to be true is going to be your reality.
Your brain is bombarded with tons of information in every second and most of it will be automatically “pushed to a side”. But your beliefs are the filters of your mind. Whatever you believe to be true, your brain will filter “those” things out from all the information you receive and you will notice only “those” things, the rest will be ignored.
So be aware of what your beliefs are. If you want to change your life, you should start from yourself. Start recreating your beliefs and you will see the change in external world.
And lastly, no matter do you believe in “Law of attraction” or not, either way you are correct. If you believe it, you will see the proof. If you don’t believe it you won’t see the proof 🙂