Your ability to achieve is a function of your self-confidence.
You self-confidence is a function of your achievements to date.
For example. the more you’ve achieved in life, the more confident you are of your ability to succeed, and the more likely you are to achieve more in life.
Your greatest achievement to date is your high-water mark.
That sets the bar for your self-confidence.
You know you can do that. Everything less than that is doable.
Push your high-water mark.