Imagine you go back in time and kill your grandfather as a baby. This would prevent him from having kids, including your parents. But if your parents never existed, then who would have killed your grandfather as a baby? A parallel universe version of you, created in a timeline where your parents didn't exist?
Or maybe it's just a big ol' mess.
This paradox suggests that a cause can be its own effect, and an effect can be its own cause. It's like a time-traveling, reality-bending, mind-bending puzzle.
Or maybe it's just a bunch of made-up words.