Cassia Rose Heatley
That still happens so far on?
Sho - Beginner
Dan - Grade
Shodan = Beginners grade
It seems trite, but it really is true. Expect to continually readdress everything you know. Not because what you're learning is wrong, but as as been said before, you need experience in one direction to even notice another, let alone start moving towards it. As a mere Nidan myself I can completely relate to the Tenkan-relearning discussion above!
Frustration is not an obstacle, but an essential learning tool. Frustration not only reveals your own level to yourself, but also gives impact to your eventual revelations, and they become all the more clear and precious because of that struggle, inviting you to improve once again. Even in the best dojos, I really don't think there's a way round it, and try to think of it as a positive aspect of learning. You will only learn as quickly as your body can absorb the answers, even from a teacher who seems to have them all.
I think of it like building a tower. Every time you get something right, the tower builds upward. Every time you get something wrong, a rock falls to the side. If you only practice the "right" way, your tower will be tall, but narrow and easily shaken. But if you allow yourself to fail, the rocks of your mistakes build up all around the sides of the tower. It goes up more slowly, but is held up by a vast pyramid of experience underneath.
Of course, every now and then you have to dynamite a level of the tower into yet another pile of rocks...