Commenting on Are your users stuck in ‘P’ mode?. I’d see the green & purple circles as about the same size, but offset slightly, like the image to the right
There should definitely be a large overlap between the two, but the product should be able to do a few things that the user isn’t up to yet, in other words it should actively help the user to ‘raise her game’ and improve. In a product for complete beginners (in whatever domain) this could simply take the form of wizards that guide the user through various tasks while explaining how to do them manually in future (and the implication here is that they explain how the manual process introduces more flexibility/options otherwise why not just always use the wizard). At the same time, the user should be a bit ahead of the product in a few areas, I feel that this is important as this is where we will improve our product for the next release. The beauty of this is that each user will overlap in a different way, so by satisfying the needs of any 2 different users we should always be able to stay in this position.
The trick to working like this is to discern when the 2 circles are starting to diverge in size, i.e. when our product is starting to fall behind users needs (the purple circle is expading away from the green) and we need to spend more effort adding the features that they need; or, when the opposite is happening, and the product is capable of doing way more than the user (this is the original ‘P’ mode scenario).