The next night a bright light started to shine in the middle of the room, and a shade rose up through the floor.
It looked old. Not old the way an old man does, or even the way old buildings do. It looked old like a mountain, like an ocean, like the stars. It was past aging.
It also looked young. Its form changed constantly, and never settled long enough to make out clearly, but it was always a child. Its face changed, its hair changed, its number of limbs changed, but it didn't age. Naturally, it wore a striped shirt.
When it had Flowey's attention - Frisk slept through it, somehow - it spoke, in a soft, pleasant voice. "I am the Ghost of Christmas Past."
"My past, right?"
The ghost nodded. Everything went dark.
When Flowey could see again, he floated. They were facing a dinner table. He knew nobody could see them.
Chara was looking at their plate, doodling with a fork in their mashed potatoes, and explaining. "People put up lots of lights. And other decorations. And then Santa gives people presents."
"Well," Asgore said in a serious voice, "I'll see if I can get him to pay us a visit."
Chara added, "And everyone eats chocolate cake."
"Chocolate cake?" Toriel asked. "I suppose I am not one to argue with traditions."
Asriel giggled.
The scene shifted. Walls fell away, trees sprang up, and they were in Snowdin.
Chara trudged through the snow. Asriel ran after him. "So - so we have to have a snowball fight?"
Chara nodded gravely. "It is absolutely essential."
Asriel stopped and looked around. "Can we do it here? What are the rules? Do you have to -"
A snowball hit him in the back. He froze. Then, a grin spread across his face. He stooped to pick up snow.
"Hey! Come back here!"
Laughter filled the woods.
"Why are you showing me this?" Flowey asked. "Do you think I don't remember? Do you think I don't want this?"
"Do you want it to stop?"
Flowey was silent for a while. "Please keep going."
There were tears in his eyes.
