Learning does not stop after the age of ten and the ability to form new memories continues throughout the lifespan. However, the brain networks laid down during critical periods are quite conservative and difficult to change. Consider how easy it is for children under ten to learn a new language and how comparatively difficult it is for their parents to do the same thing. This is often the case in immigrant families, where the children’s ability to learn the new language far outstrips that of their parents.