My mother was unflappable.
One day as she was walking to work, a man approached her, opened his raincoat and flashed her.
Without missing a beat she looked him straight in the eye and said, “No thanks, I just had a baked apple!”
It made no sense whatsoever, but it took the flasher by surprise that he wasn’t able to shock her.
She just kept on walking.
It became another oft repeated catch phrase we used for any odd or awkward situation!