Remember: everything Sans says is made up.

*Sans walked through the dark land of Waterfall, seeing the echo flowers.Waterfall was a beautiful and peaceful place. The atmosphere was mostly blue colors and some yellow fireflies. He always went to Waterfall to rest his head. He heard whispers coming from the echo flowers, which was normal: If you tapped one and said something, it would listen and repeat. He heard a different whisper, a different voice. He slowly approached where the sound was coming from, and then, he saw... You.*