Here are the boys performing that same song 44 years after they wrote it. This is the metamorphic stage.

Young and Old
by Charles Kingsley (1835)

When all the world is young, lad,
 And all the trees are green;
And every goose a swan, lad,
 And every lass a queen;
Then hey for boot and horse, lad,
 And round the world away;
Young blood must have its course, lad,
 And every dog its day.

When all the world is old, lad,
 And all the trees are brown;
And all the sport is stale, lad,
 And all the wheels run down;
Creep home,and take your place there,
 The spent and maimed among;
God grant you find one face there,
 You loved when all was young.