Suppose you want a computer vision model to start recognizing a particular object (and its subtle variations) in photos, but it has never seen this object before. How many of these objects must the model be trained on before it can generalize and recognize the object again? Now show a child some bizarre object just once, and see if it can find the object in any photos, even if the object is at different angles or subtly varied. The child will certainly do better, off just one training example.