The "Time to Lotto" thread drifts brought this to mind:

The Canyon from Horseback
 
The young don't know enough
About being young
They squander youth
And never know 'til later.

Any lad of twelve will testify
An eight-year-old can't even qualify
To be a child
At eighteen our own ignorance
At fifteen is finally written
In language we comprehend:
We know the score
Reality's the icing on the cake
Of youthful fantasies;
When the young grow old
They know a lot
About being young
But almost nothing
About being old.

From Poems of the New Old West
Copyright 2002, Jack Purcell