Who said "Your imagination is the only limit"?

This quote is attributed to Led Zeppelin.

Your imagination is the only limit - Led Zeppelin

"Your imagination is the only limit"

Led Zeppelin Imagination

Rock Band British 1968–1980

"I've been dazed and confused for so long it's not true"

"The song remains the same"

"Whole lotta love is what I need"

"Black dog on my trail"

"Imagination is more powerful than knowledge."

"The world is full of wonders if you know where to look."

"You have the imagination of a child, Lucy"

"The world is full of mysteries waiting to be solved."