What is the importance of The Nursery

The nursery, where Mary Poppins sleeps alongside John and Barbara, is a special room symbolizing innocence, youth, and magic. The babies are young enough that they still have what Mary implies are innate abilities to speak with natural elements and animals. It is only once they get older, causing them to 'grow up,' that they actually lose those abilities entirely and forget everything they used to know. The nursery is therefore clearly linked to the idea of magic and wonder as well as youth. Yet, conversely, the implication that all that magic is only temporary lends the room a certain melancholy and makes the twins' innocence appear bittersweet because it is so fleeting.