If time travel was real, and you did alter history, it would have to alter to what it is. Let's say you go back to America during the 2000 election. Let's say Gore is winning the election by a long shot. You would go in and you would alter it to make Bush win, because otherwise the Future/past/present would be on a totally different time scale, such as star trek has different time scales. (etc. I am too tired to finish my argument but still as you said TIME TRAVEL IS NOT REAL...

but if it was, I really don't know what I would do. Maybe join the army or something. just bring in a modern weapon. I don't know!