I agree. I read something earlier today that really caught my attention: the ocean covers 70% of the earth's surface, yet 95% of it remains unexplored.
This goes to show just how vast the universe is. We have yet to discover 99% percent of what is truly out there (just on planet Earth). It's crazy to seem that humans would be alone, but I think you are right-- whatever life form(s) are out there-- they are definitely not humans.