There's a fundamental difference between knowing a skill theoretically and being able to perform it practically. Theoretical knowledge offers a foundation to talk ABOUT the skill, but without practical experience, it remains abstract and often incomplete.
For instance, your friend Sarah might understand the concepts of public speaking - like maintaining eye contact and modulating the voice - yet struggle to apply these effectively in a real-world setting.
Give up on understanding in order to do. Instead, use the NLP modeling methodology to actually do, and then use the NLP code to understanding what you do.