The Theory of Relativity
You can think of relativity as if we were looking at a fly. That fly’s life span is incredibly short to us say 24 hours, but to the fly we ourselves are ancient beings who live for multiple life spans. It’s similar to a tree looking at us. They would see us as the fly living a short lifespan and dieing quickly, but to us we think of trees as the ancient beings that live for multiple life spans, so we are the fly. So as someone would approach the speed of light their lifespan would seem to increase, while everyone else’s decreased. In a sense everyone else would become a fly while we stayed human, but to everyone else were would become the ancient beings the flies see.