That's just the most extreme form. As with most things, it's a gradient.
If you know that there are things you don't know, you'll probably be more humble. If you feel overwhelmed, because there doesn't seem to be an end in sight, it might affect your confidence.
If you know that there are things you don't know, you'll probably be more humble. If you feel overwhelmed, because there doesn't seem to be an end in sight, it might affect your confidence.