Solve this mystery, please

It's known as the Origin Paradox, where the origin of something is itself. Like, if a time traveler had a kid and named it after their friend, but it turns out their kid grew up to be their friend, so the kid was named after his or herself. Sorry if that explanation is confusing, but it's the only one I've got.

*cough* Melody Pond *cough*

Yeah... I watched that episode right before I wrote that...

river is the only water in the forest

Professor Snape decided to grow his hair longer and become a hippie with intelligent thoughts.

I don't care. He still killed Dumbledore.