I'm bored at work so I thought I'd give everyone a Friday OT question to answer. It has a bit of a convoluted setup, but lets give it a shot. And its about time travel!
Scientists develop a way to travel through time, however, its not your traditional "Back to the Future" style kind of time travel (no sweet DeLoreans, sorry). Instead, they are able to take your present day consciousness and send it back in time to your own body at any point in your lifetime. So who you are as a person today(knowledge, personality, awareness, etc)is sent back into your body at any point in your own life, and you are only limited by the physical restrictions of that body. Basically its Quantum Leap, but you can only leap into yourself. Scientists can only maintain the effect for a couple minutes, so its just enough time to correct a mistake, experience a moment again, or make a small change in your life.
So the question is, where do you go back to and what do you do? Remember, you're only there for a couple minutes at most, so "take out Sandusky" answers dont work unless you went duck hunting with him once and want to pull a Dick Cheney.