Known sourcecanonical
"O Life! how pleasant is thy morning, Young Fancy's rays the hills adorning! Cold-pausing Caution's lesson scorning, We frisk away, Like schoolboys at th' expected warning, To joy and play."
Robert Burns / Epistle to James Smith.
Epistle to James Smith.
Bartlett's Familiar Quotations, 9th ed. (Little, Brown, 1905), public domain