Do you sometimes observe your mind? In the ancient Vedic scripture Bhagavad-Gita, Krishna says to Arjuna One must deliver himself with the help of his mind, and not degrade himself. The mind is the friend of the conditioned soul, and his enemy as well. For him who has conquered the mind, the mind is the best of friends; but for one who has failed to do so, his mind will remain the greatest enemy.
When you start observing your mind first thing you might notice is that you dont control it. How many times you have read something, sometimes even trying to really concentrate on the subject, but then you caught yourself thinking about something completely different at the same time?
You can observe your mind, because you are not your mind, as you are not your body (This article is not about You are not your body subject. I wrote more about it in Introduction to Manifestation)
To manifest what you want you need to control your mind. You need to concentrate, meditate and visualize often. You need to focus on the things you want to manifest. If you allow your mind to jump freely from one subject to another, like a monkey from tree to tree, it will take you long time...