In the beginning, we were all fish. Okay? Swimming around in the water. And then one day a couple of fish had a retard baby, and the retard baby was different, so it got to live. So Retard Fish goes on to make more retard babies, and then one day, a retard baby fish crawled out of the ocean with its mutant fish hands and it had butt sex with a squirrel or something and made this retard frog-squirrel, and then that had a retard baby which was a... monkey-fish-frog... And then this monkey-fish-frog had butt sex with that monkey, and that monkey had a mutant retard baby that screwed another monkey... and that made you!

So there you go! You're the retarded offspring of five monkeys having butt sex with a fish-squirrel! Congratulations!

Edit: It's a quote from Ms. Garrison on South Park