In kind of relation to this... civilizations might have been wiped out due to the many amount of reasons through out the galaxy. ( Space) Radiation, comets, meteors, ( local) disease , cataclysmic event in said place, or just plain dying out due to not being able to thrive in environment.

Randall Carlson and Graham Hancock talk about our own brushes with cataclysmic events. Possible giving our culture a bit of amnesia. ( It is a bit more complicated then that, not going into spiritual mumbo jumbo)

Podcast that blew my mind is this ONE with Joe Rogan

They discuss The Younger Dryas and the real possibility of advanced and specialist cultures, which is contrary to the current belief that we were only merely hunter & gathers.

As we came out of the Big Ice age it was a time of warming , but then all of a sudden we were plunged back in the ice age "instantly".

Randall Carlson and Graham Hancock adhere to the Impact Theory and pairs with Randall Carlson's view on the Scabland and Dry Falls of Washington to be the result of a massive flood that came pour through there from a comet hitting the top frozen area of North America. Creating a massive melt, clouding of the skies ( nuclear winter idea)

I think it is all fascinating. I am just learning more now. I realize there are lot of ideas about this. I am more interested in the idea that previous civilizations in the far past were quiet advanced, meaning specifically, they have specialized culture and had time to pursue these things. Organising of society, engineering, shamanism, and farming of crops and tending animals.

Imagine the amount of knowledge and information we have lost through out the years then we just never recover?