From watching Discovery, there was an interesting reportage on human and how in less than 2000 years we have progressed more than we did in 100,000 years, and they were raising the question of alien genetics for the missing link.
there are a lot of things that doesn't add up with the modern man. His lack of integration with his natural environment or I should say his host natural environment, is questionable. His self-destruction mentality, and his culture of building and destruction, his ability to self-regulate but at the same time to abuse things, is just NOT natural, counter productive and inefficient.
There are strong evidence that we all come from outer space, from a distant planet. With thousands of "objects" hitting earth, why would it be impossible to think that we have been visited before ? or that we are actually the invaders, not natives of earth.
Apparently a number of artifacts have been recovered, and seem to point to that direction, evidence from the Maya and Egyptian time. And of course, we have Area 51 and all the conspiracy theories.
Why would it be impossible to think that this is all true ?