h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Wow, time flies when your breathing! In the last 4 weeks I have rescued 2 lizards (1 water dragon, and 1 iguana) had a flood in my store, wrestled a giant man-eating curry.....no wait ignore that middle bit, that was 5 weeks ago. Anyway, time flies, and sometimes it knocks its head against a window for a while. Knock, knock. I have discovered the truth about time travel. You can go backwards but not forwards. Why, you ask? Because the future is determined by the events of the present, therefore the future you "go to" is only one possible future. Whereas if you jump to the past, it has already happened. The script, as it were, has been written. Also, if you went back in time and mucked about, you wouldn't really be changing anything because the "future" you are coming from is actually the present and it has already been decided by the events from the past. Make sense? A word of caution, Do Not attempt to kill your past self to prove this theory wrong. Even Stephen Hawking can make mistakes!