If you assume that the universe is infinite, or at least really really big, eventually, the arrangement of matter has to repeat. That means it's statistically probable there is another you, who lives in a "milky way", who lives on planet 3, earth, and who has lead your exact same life. Anything and everything is possible, when you consider just how big the universe is.
I think of it like a tree, every single decision that you make creates an alternate universe-creating other branches.
Ex. You chose A, then there is another universe where you chose B and so on....crazy shit.
People are thinking "man why dont they just find the end of the universe with something insanely fast..." , even light goes about 186,000 miles per second, and light will take billions and trillions and just too many years. Our lifetime might never find the end of the universe, but when you think about it, if the Big Bang Theory is correct, the universe is still expanding exponentially, and the end is just farther and farther away.
if the world is our universe then a single sand grain is our entire solar system, a solar system that even light takes hours to travel through..... we are small, small, small creatures.
Lately i've been thinking about how everything started, i mean, EVERYTHING couldn't have just started.