"When Is A Leaf Not A Leaf?" Have you figured it out yet?

When is A leaf not A leaf? (Must be spoken to be a successful riddle!) Give up? "A" leaf is not "A" leaf when it's "B" Leaf (belief)! Original Riddle by MarashGirl©2022 Note: This riddle must be spoken in order to be successfully "riddling"! N.B. With many thanks to Raffi who got Marash Girl started "riddling" all those many years ago!!!