I think it's more than this. In my case in most of images I made about basketball there were more than one ball. I'm not an expert, but some fundamental constra

I think it's more than this. In my case in most of images I made about basketball there were more than one ball. I'm not an expert, but some fundamental constrains of the human (cultural) life (like all piano keys are the same, there's only one ball in a game) are not grasped by the training or grasped partially