Instinct tells you to hide your ignorance. But this only stunts your growth. It inhibits practice. Do not hide your ignorance. Invite the opportunity to be on your edge when you rest in the unknown. Think of it as an easy way to practice vulnerability.
Certainly, there are times when I would rather die than admit I don't know something. It can be embarassing. Conquer your fear of ignorance. Know that you are safe in your ignorance. When you are transparent about not knowing, you are free to move. You can try new ideas. Experiment! Think outside the box. Innovate. Your creativity comes out to play in the unknown. Ignorance can also be your greatest leadership tool. It helps you stay honest and relate to others with integrity. It can help build your relationships and your reputation. It keeps you humble and it puts you in a place of learning.