It's not just my human mind, it's how the whole of humanity understands the nature of our universe at this current point in time.
Improbable doesn't = impossible, but it isn't as simple as Fred and Wilma from beta reticuli jumping in the family flying saucer and visiting Nevada for the weekend.
If they do exist, and if they have detected us as a planet and a civilisation worth bothering about, then the questions posed about how they actually get here require some pretty fantastical answers, but they are not completely beyond the scope of our human perception of the universe. Just because we don't know how, and we don't posses the technology to travel to black holes, never mind through them, doesn't mean that we can't conceive of the fact that could quite possibly be the secret to 'inter-dimensional' or 'warp' travel, because as we understand black holes, they appear to do some bizarre things to time and space, so it's possible some civilisation somewhere has develop the means to exploit that.
It's also entirely possible that we are, and always have been entirely alone as the only remotely developed civilisation in the universe, and what people are witnessing has nothing at all to do with ET's, because just as 'Improbable doesn't = Impossible', 'Possible and plausible does not = probable'.