Read what I will say carefully. What II will suggest is NOT the "absolute truth", it is only a possibility.
Imagine something in "2001 Space Odyssey" style, the very beginning of the film. Some intelligence gets down here, do some experiments with the most promising species and goes away to wait for the results. A few thousand years later it returns and finds a primitive society we know as Romans, and decides to try a more direct approach. But the approach do not occur well as she expected, and its representative is killed by the natives. Then the intelligence decides to wait until the natives evolve enough to be able to a contact, perhaps a few more thousand years in the future.