Consider the small colonies of animals that surround deep sea "smoker" vents. You've probably seen them on National Geographic or Discovery. These colonies of tube worms, crabs, and fish have no concept of any life beyond the immediate vicinity of the smoker vent, where they live their entire lives.
There are similar colonies of smoker vent animals all over the sea floor, but none of them are aware of the existence of any of the other millions of colonies, which are identical to theirs. For all they know, each one of them is the sum total of life in the entire universe.
Every once in a blue moon, a strange advanced craft approaches one of these colonies and plucks a few members of the colony. It flashes bright lights in the pitch black darkness to capture photographic evidence of the colony. For the residents of the colony, this must be an inexplicable and horrifying experience. The alien craft shows up, does what it does, and departs - never to return.
Humankind is likewise isolated in a vast sea of endless space. If there are other colonies of life forms residing on other planets, they're so distant from us, that we can't detect them. We also don't have the ability to travel far enough to look for them, so as far as our generally accepted reality is concerned, these other colonies don't exist.
But, just because we can't observe or interact with them, doesn't mean they're not there.
I prefer to look at the universe as a macrocosm of our own planet. We humans are a lot like the smoker vent colony on the deep sea floor. You and I know that there's a whole world of life beyond the immediate vicinity of the smoker vent, but the colony goes on without the slightest awareness of this.
I get your point and it's an interesting perspective. From a practical point of view, yes, we're just as isolated. Thankfully, however, we do have the capacity to wonder what's beyond our "smoker vent." :-)
But we are most definitely NOT like the creatures living in the ocean vents - that is what the evolutionists would have us believe. We are very special creations of God, so loved that He sent His only Son to pay for our sins and gain us eternal communion with Him. We have a revelation of God (the Bible) and the Son of God who gave his life to redeem us (Jesus). In our scripture it’s pretty clear that there will be a great deception and that the purpose behind this is to lead us away from God and towards a global, occult-based universal system of demon worship. Since the ocean vent bugs can’t claim that, I have to respectfully reject your analogy.
Besides, who would be in a better position to deceive us than phony aliens? You wouldn’t expect demons to show themselves as demons, would you?