Plausibility of ancient extraterrestrials

[Anomalocaris]

It's a rare culture that doesn't have a golden age myth.

In most cultures the Golden age myth is an institution that allows old farts who was never any good in their own youth and whose mental facilities have since further slipped to continue to browbeat younger, more energetic generation who otherwise would not take their shit.

By glorifying the mythical past, the older generation prevents rise of newer institutions dominated by the younger that would sideline the older generation.   The older, the closer to the old glory.