So, Mr. OP. it seems for you "mythology" is about things that are fictional or non-existant.
I very very strongly disgree to your basics (and therefore protesting to such views hereby). To me mythology is about "myth"s which are stories passed down innumerable generations about things whose truth cannot be established through modern "scientific" means (meaning they are unknown/unseen to modern science), but which at the same time are so popularly known and believed that they cannot be dismissed as completely false either.
My favourite Thesaurus seems to think "myth" = A traditional story accepted as history; serves to explain the world*view of a people.
And in my personal opinion, every word of mythology coming from ANY culture or people across the globe, conveys truth in some form or the other; sometimes verbatim, sometimes figurative. "Truth", that our modern science (something the average human of today are so proud about) is far too immature to see or establish. But definitely, things that very much ARE a part of our reality and affects and determines our courses through the journey of our selves from a bacteria to a fully enlightened beings to a GREAT extent.
Ithink Adamastor is awesome. A the greek giant became known among sailors and was imortalized in Lusiadas where he stood at the end of the African continent destroying ships, saw the future and turned into tears (the most ugly and montrous gian, go figure it ) after a beautifull maiden sent by Venus crushes his heart.