Great post @vikthor
I also became interested in advanced prehistoric civilisations in my late teens and like you did a lot of reading.

I found this map a while ago (not sure of the author). It now seems likely that these advanced civilisations existed over a very long time and that there were several dramatic earth changes with significant loss of life and alterations to coastlines.

A picture of several advanced prehistoric civilisations with global travel and communication does appear to be emerging through multidisciplinary research - along with some idea of their locations and timelines.

We probably have much to learn and unlearn about our deep past 🙂

Have you seen the following videos?
Atlantis:
Lemuria: