Confidence Through Mastery:

"It’s one thing to feel confident of your knowledge; it’s something else to demonstrate mastery. Testing is not only a powerful learning strategy, it is a potent reality check on the accuracy of your own judgment of what you know how to do. When confidence is based on repeated performance, demonstrated through testing that simulates real-world conditions, you can lean into it."

make it stick - Brown, Roediger, McDaniel