Crossword puzzle clue "the less traveled unlocking the poet within stephen fry book"

"The ___ Less Traveled: Unlocking the Poet Within" (Stephen Fry book)

Pithy sayings (four well-known ones containing the circled word are the keys to unlocking this puzzle's theme)

Unlocking aid

Key ___ (electronic device for locking and unlocking car doors)

Unlocking devices

Key to unlocking this puzzle's theme

Off and on (and the key to unlocking this puzzle)

"Letters to a Young Poet" poet who wrote, "The only journey is the one within. Oh, and also that band from the '80s"