A Weird Kind of Thought Experiment

Ave evelrady: I've explained this to people in the past, and they've not understood it. And i always feel like lonely when people don't understand tat. Can i tell you what? Wed i'm going to a weird kind of thought experiment that that i have to help me appreciate at the moment. A time machine could bring us back to any point in our history. But while you're back there, yo, don't know that you sent yourself back there.