> The Sage caste of india could just decide to self-immolate? Why not other people of india and why certain caste did stuff?

I think others did it too (or had it done to them?). I’m not expert and risk mangling a description of the ritual, but Sati/Suttee was where widows sat on their husbands funeral pyre or were buried alive.

https://en.m.wikipedia.org/wiki/Sati_(practice)

The Greek authors naturally were not completely versed in the ins and outs of Indian traditions so they confused different social phenomena. There was no “Sage caste” but there were different orders of monks following different philosophies. They are loosely grouped together as Shramanas and they generally believed that this world was illusionary and full of suffering and the task of religion is to find a way out. Some of the more pessimistic ones thought that the only truly nonviolent way to do it is by suicide. This is an official dogma of Jainism to this day (though Darwin has moderated actual practice considerably.)

Sati is a different social custom from a much later time period.

Seeing and sight are two different things and used to be taught as such.

> Like Augustus a Roman emperor, was initiated into the mystery of two goddesses? What was that?

Probably normal mystery-religion/club shit. We'll do the secret rituals, teach you our secret signs, impart some secret knowledge. Ta-da, now you're a 10th degree freemason, master-elect—er, I mean, are initiated into the mysteries of Juno or whatever. There are surviving fairly-old mystery religions (in addition to the alluded-to imitators of that sort of tradition, like the freemasons). They tend to be really shit at proselytizing and to not do great in a globalizing world in competition with bigger religions that are good at gaining converts, so it's a dying breed of religion, but hardly a mystery (ha, ha). Between that and limited ancient accounts, we can make a decent guess at the general kind of thing Roman mystery cults were up to.

> Why Marcus Aurelius was so wise and unique?

Eh, he wrote a pretty-good book on an existing philosophy that he'd been taught. Not nothing, but not exactly revolutionary. Epictetus, Seneca, and others preceded him. Anyway, a lot of that book doesn't get quoted in tweets, because it's not-so-wise-seeming stoic physics, metaphysics, and religion/cosmology. It's just the pithy bits of ethics and right-living that people really like. Meanwhile, in a few hundred years, Rome produced, what, two emperors whose writing we still care about at all, with IIRC 3ish volumes between them that are still read by ~anyone? Again, not nothing, but also not that out-there.

Did he merely learn what he was taught or did he start living what he was taught?

> Augustus a Roman emperor, was initiated into the mystery of two goddesses? What was that?

Yeah right? That is weird now. But I’m pretty sure the simplified version of what happened to that is is: christianity + germanic invasions..

> The Sage caste of india could just decide to self-immolate?

Fanatism has existed for a long time and “honorable suicide” too.. In that case it was about reincarnation.. I guess in modernity it’s less common because we have better options?

> Why Marcus Aurelius was so wise and unique?

I’m pretty sure he was not more wise and unique than lots of wise and unique people living today.. He just happened to be the literal emperor, and wrote a book. Also they had a Lot of really shitty emperors though..

> Why Marcus Aurelius was so wise and unique? Why later kings and heads of states and general people were not like this?

Democracy

/s

> Why later kings and heads of states and general people were not like this?

Because we only remember the idealized propaganda of their self-images.