It's About Time
"Let me just make this easy for you, buddy," Future You says. "You pick the 55-inch one. Trust me. I should know."He's told you nothing about the year he comes from or the years between. In fact, the only thing you've been able to figure out for sure about your future since he showed up in a blast of white light, naked on your kitchen floor, is that at some point you become a real jerk.
"I don't know," you tell him, looking at both models in the department store. "A 47-inch LG 1080p 120Hz LED HDTV seems more than adequate for my needs."
"OUR needs," Future You corrects. He's been sleeping on your couch for about a month now with no signs of leaving any time soon. Whenever you bring up when he might return to his Present, he laughs it off, says something about having all the time in the world, and then asks if you could pick up some beer on your way home from work.
Future You didn't bring any money with him from the future. Apparently, inorganic material is destroyed in time transit. He also refuses to get a job because he might adversely affect the time-line if he screws up someone's drive-thru order. Unless, of course, he's already done it in this timeline. He's pretty sure he hasn't, though.
"Aren't you not supposed to use your future knowledge to affect my decisions?" you say. "I thought that was a rule or something."
"Uh, well, not when it's a matter of, um, great importance. And, dude, it's really important we play video games and watch movies in full 1080p HD with TruMotion 120Hz technology on something HUGE. Seriously."
Even though Future You refuses to talk about the future, you've noticed things. The ring of pale skin where a wedding ring might have been. The awful scar on his right arm. The way you hear him cry out about robots late at night, only to sob himself back to sleep. He seems lonely, desperate for companionship, so you put up with him. He is YOU, after all. But your patience with yourself is beginning to wear thin. "So what happens if I don't buy the 55-inch HDTV?"
Future You shrugs. "The space-time continuum will rip asunder, causing history itself to unravel and all of existence to become void. Usual stuff. Now let's get a salesman."
"Would it? After all, if I bought the wrong size HDTV, even though it had the same 100,000:1 Dynamic Contrast Ratio, amazing brightness, and color detail as the other one, it would only set into motion a chain of events that may change who I am..." You smile and look directly into your own, slightly older eyes. "In the future. I wonder if being if you existing in the new timeline I create by choosing the wrong HDTV means you won't be affected, or if it'll be more like Back To The Future and you'll just painfully fade out into nothing."
"Um." Future You looks down at his feet. "Now that I think about it, I think I remember buying the 47-inch one. Jerk."
That night as you're catching up with Game of Thrones, Future You will sit down next to you on the couch and proceed to spoil the whole series. Before you storm off and close your bedroom door, you'll hear him say, "Geez, I forgot what a real stick-in-the-mud I was."