As limited human beings we can't be aware of everything. With all the noise, clutter, and distractions of life, wWe become aware of the things that are important to us. For example, for a mother with a baby, she hears the infants every cry. As a dog owner, I'm aware of the single scratch of my dog against the door when he wants in.
The same is true in becoming aware of life principles.
That which we focus on is that of which we become aware.