So ... Superman, Jr. goes back in time to save his father, thus changing all history in a moment.

H. G. Wells: It's the butterfly effect.
Yoda: Always in motion, the future is.
Wells: Even when it's the past? And what are you doing in this universe anyway?
Yoda: Boring, Dagobah is. If change the past, the future can, then ... meditate on this I must. But first, a trip to Disney World I must take.

Quote
Clark looked at the wall behind them. Sure enough, there was a small hole with a greenish glow where the bullet had landed. "But, wait a minute," he said, thinking very hard, "If I was shot, how could I then go back in time to save myself?"
Assassin: That's what I'd like to know! I know I succeeded -- except I didn't. But I did succeed! So how come I didn't? Does this mean time travel is real? (light goes in the assassin's head) Oh, the possibilities!

Great story.

"Oh, you can’t help that," said the Cat: "we’re all mad here. I’m mad. You’re mad."
"How do you know I’m mad?" said Alice.
"You must be," said the Cat, "or you wouldn’t have come here.”

- Lewis Carroll, Alice in Wonderland