In many ways we become what we think. What you say to yourself becomes how you view yourself and eventually, gradually, who you are. If you are exposed assiduously to a notion, it eventually becomes true to your mind. Hear something enough, and you believe it.
A lot of people are intimidated or even terrified by this notion. They want to view their minds, their personalities as something whole and immutable. Something that remains unchanged amidst decades of sensory stimulus. This is not the truth of the matter, however understanding that the mind is continuously being hypnotized by its surroundings allows you to do something about it.
You can choose your hypnosis.
Advertisements, ideologies, political platforms, messages from every medium are constantly bombarding us, and swaying our subconscious whether we like it or not. See a product enough times in a positive light, and we begin to see the product as favorable. Get told a lie enough times over the television, and we believe it (see: vacations will make you happy, you have a chance at the lottery etc)
What we can do about this, is exactly what other forces are doing right now. Tell ourselves what we want to believe we are, even if it is a lie, and do it often.
When we repeatedly affirm to ourselves a given idea of who we are, it can alter our perceptions and even our performances. Even something as simple as “I am powerful” “I get up early” “I spend my spare time reading”, if listened to enough, will gently work its way into the subconscious, and become who we are.
Yes this is as goofy as it sounds, but it also the secret weapon of some of the most successful individuals on this planet. Get in front of a mirror, practice your best booming speaking voice, forget about the silent judge inside, and tell yourself who you are!