My beliefs that Cassie is an alter ego of Bree's comes from several 'clues' I've picked up on by watching the videos.
Bree went to high school for a short while, where she met Daniel and Cassie. Her and Daniel have remained friends for the two years following
while Cassie 'disappeared' after Bree went back to homeschooling.
Apparently the girls were friends. Brought together by the commonality of isolation. They were both loners. They were both picked on by other students. They walked the track together...yet, Bree can't even remember what Cassie looks like.
Daniel doesn't remember anyone named Cassie at all. As we know, Daniel has the hots for Bree. He's considered their outing as a date and he's kissed her, expressed feelings of 'like' etc.
Bree, back when she was responding to the earlier YT videos tells someone that Daniel likes someone in his class. She won't tell the name because Daniel might get mad. This may be in the YT response section under #4 The Danielbeast, I'm not sure.
Why was Bree put back into home schooling? Is it overly religious parents or is it concern for a mentally ill daughter?
Did 'Cassie' have a fling with Bree's 'star' teacher? Bree may not be the virgin she thinks she is. Could this little detail destroy whatever ceremony is coming up?
In the Park video, Bree wasn't herself. I'm thinking we may have been watching Cassie in this one.
And Lucy...the helper. Perhaps Lucy is a psychiatrist helping Bree past her delusions. Perhaps she is a member of the Order and is helping Bree incubate her other self. Either way, thoughts of Cassie emerged after Bree's introduction to her. Also, it appears that something from the Swimming video triggered her memory as well.
In the Thelema philosophy, there is a belief in the 'secret self' or higher self which acts as a guardian angel for the regular 'self'. It was actually (or so he claimed) Crowley's secret self (Aiwass) that wrote the Book of the Law.
So there it is. HenrySugar's theory on the Lonelygirl15 saga. If anyone would like to add to or discredit, I'd be obliged to listen
