Caps and gowns. Parties and celebrations. A milestone in the lives of thousands of youth. From that time forth, they can never retreat to the safety and predictability of their former life. Few want to, but even if they want to cling to the known, it is past.
Graduation is a launching.
The shore must be left behind. Uncharted waters are ahead. That can be both exciting and frightening. No guarantees for success are available. Some sink and some swim.