Time travel, so far as conventional wisdom goes, doesn't exist, otherwise we would have spotted time travelers by now. I'm here to tell you that we handle it with a little more sophistication than you might have been led to believe.
Just picture it: a society that has made time travel a reality probably has a little more going for it than you are generally capable of conceiving at the moment. Time travel itself is viewed in my time with a little less romantic underpinnings than you yourself no doubt currently consider. Think of it like traveling to another country. Who but the very rich or very determined or very busy even begin to consider it lightly? There are countless things to consider, just in trying to reach another place in your own time. There are languages, inoculations, plans that need to be accounted for. To travel to another time is to take all that and plus many more things in mind. For one thing, anything that has happened has already happened. You can't change time. You can only create a parallel, separate reality. If you attempt to alter the past, you will only succeed in branching off into irrelevance. No one travels to alternate realities. That's the stuff of fiction. You quickly learn that any change is simply a novelty, and that there are a great many other things worth doing with your time.
So, those who commit the act of time travel must really be determined. There is nothing to gain from it, since access to the future is impossible, and access to the past is only informational. I offer my own experiences in testament.
I had for a number of years become enamored of the writer Thomas Hardy, having grown a deep personal connection and identification with the alienation he wrote about in books such as Jude the Obscure. I considered it worthy of my time to visit with Hardy himself, to compare reality with my fantasy. I made all the necessary preparations, and after five years was finally able to make the trip. I found myself in a coffeehouse, and to my astonishment, the man I found seated at the adjacent table was none other than Thomas Hardy himself. I shouldn't say "astonishing," because that was exactly as it had been planned, but to actually see the man was beyond anything I had imagined.
For one thing, he was old. I hadn't really considered that. You never really picture someone in history as old, unless you have been exposed repeatedly to pictures of that person only in old age. You generally think of someone, regardless of context, more or less as you think of yourself. You expect them, especially if you identify with them, to be almost a mirror image, though certainly not with your face, but familiar enough so that you might as well known them all your life.
That was not as I then saw Hardy. I saw an old man, and not a particularly miserable one, but all the same, an old man. In my mind's eye, I tried to keep the young man I had expected to find alive. This man was nearer to his death, a vaguely disappointed but still satisfied and generally lively gentleman. I considered what I might say to him. I had trained for this moment for five years, and now here it was, exactly the fulfillment of my wildest dream, and I couldn't bring myself to even speak!
I immediately rushed out of the coffeehouse, not even bothering to glance over my shoulder to see if he'd noticed. How couldn't he? But why would he bother? I meant nothing to him, and Hardy, who had meant the world to me, now seemed to mean nothing to me as well. I was petrified, embarrassed.
I kept blinking back the illusion of the young Hardy. I couldn't look anywhere without seeing him, the young Hardy, not the old man whom I'd just unceremoniously left. I also struck up a conversation with this illusion, just as if it were real, as if this phantom were Thomas Hardy, and not the specter in the coffeehouse.
I lingered for a brief time, in the past, in the future of the man I had come to see. I had been caught in my own ignorance, my inability to grasp what had been inevitable. The man who had written Jude the Obscure was that old man, and not the young one I couldn't escape.
Next time I will be more careful.