Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out.
Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning.
We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.