As children, we are subject to our parents’ situations. When they are in the habit of not getting what they want, they teach us how to not get what we want too. This is how we learn that “you can’t have everything you want.”
Truly, when you are aware that desire is simply an acknowledgment of contrast between what IS and what you would PREFER, then the corresponding energy is guided toward your preferences. But when what you desire is simply regarded by you as something YOU DON’T HAVE, then the corresponding energy is guided toward that, what you don’t have.