How to be aware of our current self believes?

[Kay100]

I wonder which of the leo's videos talk about how do our self believe form and what are the ways to identify our current negative self believes and change them?

Does a 15 year old already formed all types of self believes? How to help them realize what kind of self believe they currently have? Usually if you ask a 15 year old what kind of things he believes about himself, they would usually say "I don't know". What are the best ways to help them be more self aware and practice self reflections?

I think it's a lot easier to change the negative self believes of a 15 year old than a 35 year old right? It would be lucky if someone can start intentionally cultivating positive thinking patterns from the age of 15,.. Not everyone has the chance to learn about all that....