Can you be a wallflower and have power? Probably not.
Can you be silent and have power. Yes, there is a difference between sitting on the sidelines and not engaging and using silence effectively.
What does boldness have to do with power?
Think about it. Do you, would you, follow someone who was timid or unsure?
Being bold shows you are have energy and fearlessness and willingness to fail. Not being afraid to fail is essential. Understanding this is critical. Failure is always a possibility but it is not, and cannot be, what stops you.