No apples

We'd just thrown out a set of yellow and green printed cot sheets with apples, hearts and a few other little pictures on them, because they had a hole in them. We put a set of plain green sheets on the cot, but the green sheets didn't have a pillowcase and we'd kept the pillowcase from the patterned sheet set, they matched the green quite well, so we just mix-and-matched them.
The result? One day, a very tired toddler refused to get into bed because her sheets had no apples on them, and her pillowcase did.