I always found the structure of time as interesting. It feels as though time is just a constant thing that moves forward and is the same for everyone, everywhere, but that doesn't seem to be the case.
Imagine where you are right now, both in this moment in location and in time. You have a history of all of your past experiences: everyone that you have encountered, everything you have seen. However, there are things outside that space.
Obviously due to not being alive to have experienced events from centuries ago, but also because they would have been outside your vision due to being so incredibly distant. The same is true for what you can experience in the future, who you will meet, and the possible events you could ever see. The boundaries are limited by the speed of light and compose what is known as a light cone.
Every observer has their own light cone and where they overlap, they have shared experiences (or I suppose possible shared experiences). Even this doesn't give a full picture, as these are influenced by gravitational waves, stretching and compression, just as air pressure creates areas of compressions and rarefactions. The very structure of time at the incredibly small level even appear to be continuous.
Perhaps the concept of continuity is a bit of an illusion not much different than the pixels on a screen appear to show a continuous image moving across the screen. Even the concept of what time is has been debated and refined by great thinkers like Aristotle, Newton, Leibniz, and Einstein. Does time exist if there is no movement or is movement necessary for time to exist? Is there a fixed standard for what time is or is time experienced in different ways?
While everyone in the world can consider themselves to roughly be sharing the same "now" we still have a system of time zones that can make things confusing when talking about, say 12 o'clock unless we give more detail on where we are located. The fabric of spacetime is like a field that can bend, move, warp, and undulate which influences what is in that field. It is not simply a stage where things occur with a fixed taking that is felt the same by everyone. I hope in the future we can better understand the nature of this reality and I appreciate your time in reading!