Fake it 'til you make it
"Fake it 'til you make it" is a common English idiom, which suggests that by imitating confidence, competence, and an optimistic mindset, a person can realize those qualities in their real life. It echoes the underlying principles of cognitive behavioral therapy (CBT) as a means to enable a change in one's behavior.
The phrase "fake it 'til you make it" is similar in meaning to the idiom "act as if", and is also similar to Aristotle's idea that to be virtuous, one must act as a virtuous person would act.
In the 1920s, Alfred Adler, a disciple of Sigmund Freud, developed a therapeutic technique that he called "acting as if". This strategy gave his clients an opportunity to practice alternatives to dysfunctional behaviors. Adler's method is still used today and is often described as "role play".