Time travel fiction brainfart.
@Taylor It's not all that unnatural, even. Time travel scenarios sort of just fall out of special and general relativity, they're just very very hard to set up.
But really, at the heart of things, isn't it just an outgrowth of the very human desire to undo something bad that just happened? We can conceive of a world where the embarrassing thing we just said didn't happen, but why can't we go there? All the counterfactuals we can think of that can't be real worlds.