S1, the eight-year old, decided that he wanted a strawberry shortcake. "I too want a strawberry shortcake," said S2.
"But," I protested, "you've been looking forward to a banana split for a month!"
"I want to get the same thing as S1," she said. So, strawberry shortcake it was.
"You need to do what you want to do," I suggested, "and not just change your mind because S1 is doing something different."
"But I want to taste what S1 is having."
"S1 would have let you have a spoon of his ice cream if you'd asked him. You didn't need to also get the same thing."
"What if I have a taste of his ice cream and it is way, way better than mine?"