something that happened in the nineteenth century is that european pseudo-intellectuals went out looking towards the "oriental" world, in search of "ancient wisdom", under the assumption that the eastern cultures were older & more wise.

thus spoke zarathustra, after all.

in fact, zoroaster was seen as a massive dilettante once they could actually translate him properly.

and, it turns out that what these people were looking for was really right in front of them the whole time - those supposedly oriental & eastern ideas seem to have actually originated in the west, after all.

so, you'll hear people wonder if jesus went to india and brought back ideas, which is just silliness. jesus never existed at all.

but, in terms of it's coherence as an idea, it seems increasingly more likely that the greeks brought their ideas to india than that they found their ideas there.

that said, you can trace this stuff to weird cults in greece that appear to have iranian origins, which is not hard to make sense of. the orphics were apparently a christian-like cult that claimed origin with the scythians, who would have lived in the steppes and spoken an iranian language. you can build a very early model of cultural diffusion across the steppes that would have moved ideas from central asia into both greece and india with indo-iranian speakers, much as the vedas record the movement of indo-aryan peoples into the subcontinent.

but, it's funny what the archaeological record will tell you if you let it, huh?

gotta do those experiments, in the end - because neither racist europeans nor nativist indians would have guessed that buddhism was fundamentally greek, despite the obvious cultural interchanges around it.