PAA – I wasn’t coming to explain, I was simply making the connection! You are right, it doesn’t work in “real life”, or in practical nonhalachic concepts.
Is it so difficult? Time Travel will mean that as long as in some point in the future one would do go back in time and do x, then already the first time round x must have happened. So as long as x has happened, you will be able to go back in time to facilitate that. However if x hasn’t happened, it is not a ???? in itself, but would be a ???? that time travel didn’t happen. Why not? Dunno. But like Dumbledore explains in prophecies, you don’t HAVE to fulfill them, you just WILL fulfill them.
Enter ?????/????? debate now.