It's like this, Joseph old friend.
Forget "aliens". Forget "space travel". Forget "time travelers". Forget all of that. And try to look at it with a much less narrow perspective.
In 1942, South Pacific islanders witnessed airplanes flying overhead for the very first time.
What did they report when they saw this? They reported seeing "large silver birds" in the sky. That is because they could not conceive of what they were actually seeing. They had no conception of an...