Re: Shodan is another start of Aikido?
I certainly agree with the above sentiments, most especially that each time you step onto the mat it is a new experience, but I also think there is a definite place for training towards a test. It is an excellent time to focus specifically on a set of techniques, making them as right as you can possibly get them, in the time before the test. It is a very different feeling (for me, at least) than regular training. Less width, more depth.
Cheers, and best wishes for your training,