Hmmm... see, there's an interesting thing.
I started Aikido at the beginning of August and I wasn't planning on grading at all to start with, at least not for the first year. After a couple of months sensei said that I should go for my first grading.
This duly happened and the examiner came from elsewhere in the country and much higher in the organisation and graded us in a non-partisan way, as it were. I was more than a little suprised to then be announced as 4th kyu... skipping a grade completely.
Any insights gratefully received...
First of all, congratulations on your new rank.
In my humble opinion, this situation looks a bit fishy. I see two problems here. One, you tested after a couple months with no background in any MA whatsoever. I don't know how often you practice, nor the extent of your abilities, but most people after 2 months of practice are still trying to figure out what feet goes where, and how to get their ukemi up to speed. If I said to the average two month newbie: "quick, Ushiro Tekubitori Kotegaeshi!" They wouldn't know what to do...
The second problem is that you were not graded according to a syllabus.
I my organization, you have to accumulate a certain number of hours prior to each test. When that requirement is fulfilled, and you are deemed ready to test, you have to learn the techniques set by the organization for the particular Kyu you are testing for. Everyone is graded under the same standards.
You would need about three months practicing every week day (5 times a week) to be eligible to test for 5th Kyu in my organization. A big commitment if you have a busy life.
I have seen cases of people skipping a kyu rank. The difference is that they had to perform the techniques required for BOTH kyus. No freebies. Needless to day these aikidokas had a lot of hours under their belts and were very good.