No matter how farfetched, just post it.
Mine is that all existence is happening at any one point, there is no past or present, there is only what we're experiencing. Anything that happens is fated and affects us all in some way. It would be impossible to change something via time travel or knowing the future because it would've already happened, and your time traveling change to what happened is in reality what actually DID happen. All existence is a film, and we only move forward on that film or, in the case of time travel, backwards.
I came up with it after watching a "That's So Raven" rerun, to be honest.