Hi William, I've been training 20 and I still goof a lot of the techniques! It's just part of learning.
To answer the original post, I think most people feel they don't deserve their rank when the get it. I felt like a fraud in my hakama for about six months. Actually, I have found that each time I've tested, that it takes about six months to actually finally attain the rank that you were just promoted to (if even then, sometimes still feel like a fraud, and a complete goof, but maybe that is just me).
take care, and train hard!