A few bubbles "decide" to fly away. The design is meant to encourage escaping the "safety" bubble, pretty as it may be, and "spread your wings" as a form of occupying a space in the world and under your own initiation. Traditionally a young person becomes an adult after a ritual of successive events. This way every individual has his/her created tradition, a way of being, where there is no more "birds of a feather flock together".
Create your own tradition