Knowledge vs. mastery. Just because you know a scale or a chord or a song doesn't mean you do it well. Just because you can do it well doesn't mean you can do it perfectly. Just because you can do it perfectly doesn't mean you can do it perfectly, with feeling and passion. Just because you can do it perfectly with feeling and passion at home doesn't mean you can do it perfectly with feeling and passion before a crowd. As you learn something, you're trying to move it from bare knowledge (I understand it) to functionality (I can do it) to proficiency (I can do it well) to mastery (I can do it whenever and however I want to). Some techniques and ideas may take 6 months work (or more) before they become natural.
To have an awesome band, each member needs to be a strong, dynamic player, blending, but not depending on the others to get things right.