Untitled XIII

You ever hear that foreign noise in the background and can't figure out what it is? When you find out what it is you're like, "Oh! That's what that was? It sounded like (insert name of noise)". ...that's perception...so with that said, for those who don't believe in other intelligent life forms, is it plausible to say others walk among us or share a galaxy with us, and we don't know it because we don't know what they look like? Remember, when the indigenous people of the Americas saw the Spanish for the first time, they described them as floating on the sea, these people were God-like to them because they had never seen ships before. When
one's mind doesn't know what something is, it doesn't exist, its something magical, you can't even fathom the
thought. Aliens could be right in front of us and we wouldn't know because we don't know what they look like; we only have what Hollywood has drawn out for us and sketches from people who may have been abducted; that's not really solid information for one to go by. If  the indigenous couldn't see ships, its possible we can't see other species or other species ships as well....until they present themselves in the near future. I could be wrong...