Several decades from now, if I haven't killed myself with my mass consumption of butter, I'll be an old lady telling a room full of one-eyed, autistic children how in my day slick mammals swam through the sea. We called them dolphins. They were like fish except they were warm blooded and really smart. Some people could talk to them and they helped the Navy fight against nuclear missiles. Little deformed children would look at me and emotionally inappropriately scream at me, "LIAR! Rar."
I'd tell them no. I'm not a liar. This was way back when, when I was a young woman. Back when most people had two eyes, humans looked pretty much the same with the same number of toes, fingers, heads and what not, and people could empathise with each other.
The children would start banging their heads on the floor and start crying, "Dolphins, no. Wierdo. Dolphins lie, raaar!" And that's when I'd realize that unicorns must have existed at some point, we probably just hunted them out of existence. I'd get up from the group of children and head to the drugstore. I'd have come down with a little case of the cancer and I need to get some Bayer over the counter "Cancer b Gone."
The children will think I'm crazy but i'll know that dolphins once swam in the sea and they slept with a half a brain at a time so they wouldn't drown.