Eh I realized that time-travel into the recent past would kill anyone that did it, that the closest you could get would be around six years before, for reasons that would make this an unnecessarily long post xd
What if everyone on Earth screamed at the top of their lungs every time they woke up from a nap? The first person that woke up would scream and likely wake up someone else, who would scream as well, and then a vicious domino effect would take place as a wave of screaming sweeps across the world, touching everything and everyone save for a few losers in the deep off-grid. No one would ever be able to get to sleep because of the screaming. That's my shower thought.
The Earth and the Solar System are constantly moving. If you have to appear in the same physical location when you time travel, then it would be certain death.
..You're right, I didn't remember that. My epiphany is a bit more convoluted. Are you familiar with the Law of the Conservation of Matter? It entails that the amount of matter in our Universe, be it in the form of energy or physical particles, must always remain the same, no matter what processes occur. By traveling back in time, you're basically removing the matter that makes you up in the present and adding it to the past, which is a big no-no. (I came up with this in tenth grade, and, as I'm writing this post, I came up with a counter-hypothesis, but let me finish before I reply to myself lmao). Add to this the fact that humans take around 6 years to replace all the matter that makes them up, and an interesting problem comes up: where would the matter that comprises you come from, if you go back in time? Would the particles stay the same, or would you somehow force particles from other places to create you?