Occam's Razor dictates that the theory with the least assumptions is the most likely to be correct. Which is more likely - that somebody mistook what they saw for an alien craft; or that an advanced alien civilization has traveled thousands of light years to fly around our planet undetected and without any attempt at communication? It's one thing to remain open-minded; it's another to believe in something without evidence.
Why is an Alien visit any less likely than some other explanation ?
Just because Earth assumes
this or that theory, does not automatically mean that our
Science is 100% correct.
The Universe is a very big space, with uncountable millions of worlds and other realities.
Earth isn't the oldest planet either.
There could very well be much older and more advanced Civilizations.
There can be other Dimensions which we don't even begin to understand.
Just because Earth people do not know how
to travel vast distances of Space, or travel between dimensions, is no proof that it can not be done.
Humans have quite an ego, assuming that we are the one & only.
I don't know what you accept as evidence
, but I personally do not believe that all witnesses are kooks, liars, uneducated.
Not all videos, photographs are faked.
witnessed non-Earthly craft and other Intelligent beings.
We are not