We are what we think. Awareness and perception (the ability to understand the true nature of something) makes it possible to obtain, distinguish, and understand information about it. We have the power to choose our perception. Anxiety limits perception.
There are varieties of factors that influence perception:
Willingness, past experience, motivation and emotional state of the subject, confusion, misery etc.
“All our knowledge has its origins in our perceptions.” – Leonardo da Vinci