So here's something to think about.
If you had the option to travel back in time once, and then travel back to the present, what time would you go to, would you remain, or what would you change before returning?
Think about the possible consequences of your actions. Would you really want to risk changing something huge in world history if it may result in something awful further along, or totally change the world as you know it today upon your return?
Or, you could go back and change something in your or another person's life. Maybe go back to get yourself to change a decision you made that you now regret, or try to get someone to take a different path than the one they took?
inb4KILLHITLER