The reason a configurable product relies on child simple products is to keep track of inventory--the simple product is the physical, shippable unit (Crew Neck Shirt-Red-Small) and the configurable product, as you know, is a "meta" product that groups all of the (Crew Neck Shirt-Some Color-Some Size) combinations together.
If you don't care about having your Magento store track inventory, then you can use a simple product with custom options. This is usually used for things that you make on the fly, like monogramming a t-shirt, or screen printing a t-shirt. Create the simple product and take a look at the Custom Options tab on the left side. There you can define a drop-down for your size and specify the options there. Unlike a product attribute, however, I'm pretty certain that you'll have to re-create the size options for each product that you decide to sell this way.
The Magento Web site has a video tutorial that shows how this works. You might show that to him.
I don't think you'll find too many arguments that the Magento admin interface is extremely confusing--even for computer savvy users--but it is what it is. Good luck!