Adding subcategories

I have tried to add subcategories but I am really not sure how to do this, I have looked at the doc and it does not really show in detail. I set the category and then I tried to add a sub category and I get the following.

I have the Category and the subcategory is there, but the main category is there again also. I really am not sure what is happening, is there any doc that really tells you how to do this in detail, I guess I am a detail person when it comes to this.

You create a subcategory the same way you create a normal category

The only exception for subcategories is on the Data tab, you select a parent category for the current category to live under

I tried that, and I get the following:

1: My Category
2: My subcategory under the category which I want, But? I also get My Category listed as a subcategory.
So I got the following:

My category
subcategory
Mycategory

I am trying to figure what I did wrong?

I got it, I was leaving out a step, thank you