Crossword puzzle clue "pebble in one's shoe e g"

Like the magic pebble in "Sylvester and the Magic Pebble"

Pebble in one's shoe, e.g.

"It isn't the mountains ahead to climb that wear you out; it's the pebble in your shoe" speaker

You might pick up a pebble in one

Left shoe, to the right shoe

Felt shoe in a shoe

Store whose shoe department has its own ZIP code (10022-SHOE)

"Shoe the horse, shoe ___"