My Opinions: Time Travel

Recently I have been thinking a lot about time travel. I have watched a few documentaries on the subject. I don't pretend to be an expert on time travel, but I have a few opinions I would like to share. I really have no idea what I'm talking about.

Time travel is possible. In fact, you're doing it right now. You're traveling through time in your little bubble of existence going forward, always forward. Time travel to the future (in my opinion) is definitely possible. To travel 500 years forward in five seconds isn't bending the nature of time, all it does is speed up the process. But what if you would like to travel into the past. Is it possible? I personally don't think so. In this post, I will explain why.
To make this more understandable, we'll talk about you for a while. Lets say you are living a happy care-free life. Everything is wonderful and you are surrounded by butterflies and sunshine. But one day you make a giant mistake. You leave a casserole in the oven while you are out frolicking in a meadow and your house burns down. This is not a very pleasant turn of events, and you'd really like your house back. So you hop in your time machine, go back in time a couple hours, sneak into your house and turn off the oven before your house goes up in flames. Problem solved.
Except, not really. First of all, did your house burn down or not? This does, at first seem obvious. It didn't, because you went back in time and prevented it. But think again. The reason you went back in time in the first place was to stop your house from burning. Why would you have gone back in time at all if it hadn't burned down in the first place? So does that mean the your house actually did burn down? But if that's the case, your house should technically not be there anymore, but it is, since you went back in time to save it. In this case, there are two versions of reality. One in which your house burned down and one in which it didn't. Both realities are equally true and you have memories of both realities taking place.
But what about the innocent bystanders? What do they remember? Lets say you have an elderly neighbour named Mrs. Marmalade. She lives a peaceful life of knitting in her rocking chair and reminiscing about how wonderful the old days were. Then one day, her peaceful existence is brutally disturbed. She looks out the window to see that her neighbour's house is burning down! She calls the fire department and they rush over right away, but they're to late to save the house. Your house is destroyed. But wait, it doesn't matter. You went back in time and saved the house anyway. So Mrs. Marmalade never called the fire department in the first place. She didn't need too, the house was never on fire. Let's take a peak into Mrs. Marmalade's mind. In her memories, the house never burned down and everything that day passed by completely normally. But in your memory, the house burned down and you went back in time to save it. Your memories and Mrs. Marmalade's memories of the same event are completely different, which is impossible, right? Well, no. Technically, two people witnessing the exact same event might see it in different ways. This happens all the time. Humans do not have perfect memories.
Let me make this situation even more confusing. Lets say that Mrs. Marmalade is actually an evil mastermind disguised as an old lady. She hates you quite a lot (lucky you) and so one day she randomly decides to go back in time and set your house on fire. (You may wonder why she went back in time to cause the fire instead of just doing it in the normal way, but this is because the original version of herself was sitting on the porch knitting at this exact time. Anyone watching would conclude that it was impossible for the old lady to have set the house on fire. She was sitting peacefully on her porch when it happened.) So Mrs. Marmalade goes back in time (unknowingly to the exact day that your house burned down in the first version of time) and sets your house on fire, making it seem as if the fire was caused by you accidentally leaving the casserole on. Then she leaves the scene of the crime and returns to her regular time. You get home to find that your house has burned down, and so you go back in time a few hours and turn your oven off.
Now I will ask you the same question again. Did your house burn down or not?
See what I mean? It makes no sense. It's pretty much impossible to figure out what actually happened.
In this example, I assumed that time is flexible. I assumed that it is possible to go back in time to change things that already took place. But this model is impossible. If you change something in the past, it will have already happened when you go back to the future, meaning that you never needed to go back in time in the first place. But what if it were possible to go back in time, but not possible to change the past. Let's say that you go back in time to save your burning house again. But, for some strange reason, your brilliant plan doesn't work. No matter how hard you try, you cannot save the house. You are somehow prevented at every attempt. When you get back to the future, your house is still gone and nothing has changed at all. This model makes way more sense in my opinion. In this universe, both you and Mrs. Marmalade have the exact same memories of that day. In both your minds, the house burned down and it no longer exists. But there's one slight problem. What exactly was preventing you from changing the past? It's not like the world can just randomly stop you from doing something as simple as turning an oven off. It's not against the laws of physics.
So, even if time were solid and unchangeable, backwards time travel still makes no sense.
And then there is another problem. If time travel is possible, and we invent it in the future, why aren't there any time travelers coming back in time and messing with us right now? Why not go back in time and save the Titanic from sinking? There are a few possible reasons for this.
1. Time travelers have indeed come back in time and messed with us, but we don't know it. We think that the Titanic sank in the original version of time due to a tragic accident, but in reality, some evil mastermind from the future (maybe Mrs. Marmalade) decided to kill a bunch of innocent people for no reason by plopping an iceberg in Titanic's path.
2. Time travelers have come back in time, but they can't actually change anything that already happened.
3. Time travel is impossible.
I don't know which possibility is correct (how could I, unless I am actually an evil mastermind disguised a 14 year old girl). Maybe there is another possibility that I haven't thought of. Maybe the humans of the future have enough problems of their own to deal with and don't have any interest in solving ours. Or maybe the universe is actually going to randomly implode in 56.9 seconds and we humans never do get to that time travel stage. We can't know the future for sure, at least for now, and so I will leave you with a bunch of random thoughts that make no sense and a headache from thinking about unsolvable paradoxes. Have a nice day.