I have a problem, which I'm going to use to test whether time travel ever exists or not.
I want food, but when I walk around too much, it makes me cough more and feel dizzy.
If I, or anyone who reads this, is ever a time traveller, I would like you to arrange to have a lunch waiting for me on Friday, October 29th, 2010, 12:30PM PST, at my office. Please put it in the fridge in the kitchen, or on one of the tables, clearly marked for me. "David" will suffice, as there's no one else in the office with that name.
Thank you, time travellers.