Here is what I thought

Rating: Null/10 (15 January 2006)

Donnie is a teenager with psychological talent / issue that most don't have. He sees things in life completely differently than most of the people that surround him. I also sensed some struggle in his mind regarding existence of greater power in the universe. (While he is talking to his shrink, she calls him agnostic rather than atheist.)
Roberta Sparrow is another individual with similar power perhaps greater than Donnie knows it all and the book is about time travel for such individuals such as Donnie.
Donnie can travel through the time as he discovers the ports through everyone's chest (as shown in the movie). I took that as; every individual is an event with a specific time stamp. Time is human created and if you assume that it does not exist then only thing exists is big vacuum of universe. There has to be short cuts to travel where you came from and to where you can go.
As the movie shows Donnie's discussion with one of his teachers ... there can be more than one ways the life can be interpreted or directed. It is only possible when you know which direction to travel. Frank is artist (?) who draws rabbits and will happen to wear rabbit costume on the night he will get killed by Donnie (in Donnie's life) they both don't know each other. At the end, my conclusion for this movie is:
You can take life in the direction you want. The way to do that is to acknowledge the greater power in one's life. Time travel is not possible in today's world but movie shows that Donnie was able to direct his life in completely different direction starting from the point when plane engine crashes into his room. He is saved from that incident by greater power for a purpose  he is the "living receiver". He only gets the messages from Frank the rabbit. Roberta Sparrow knows about these living receivers and manipulators in the time travel philosophy. At the end, after he kills Frank (the unknown guy) and his girlfriend is dead he chooses to go back to the event which he knows would kill him. He perhaps has no option or he thinks that's the best possible option for his life.
A very good movie that generates thoughts!