No that wasn't quite what I said. It really depends on if you believe that Gautama Buddha was a historical person that existed, and attained enlightenment by himself without external influence, and that western Nepal was the epicentre. Doesn't matter really though, post-buddha Buddhism was coloured by culture anyways.

But yes for sure Hindu influence, just look at the art, but the real question is, where did Hinduism come from? I'm not sure. The whole situation in South Asia is so complex, so I drew a map. I know it's a mess, but I hope I can explain it well enough so it becomes clear what I mean. This not a map about the spread of Buddhism, but about the spread of culture & genes. Most of it is pretty certain, some of it opinion. But the real hypothetical paths are the arrows marked with a question mark.

Green circles mark locations of ancient high cultures.

Turkey Göbekli Tepe

Pakistan/India Border Indus Valley Civilization

Cambodia Khmer Temples

Indonesia Former Continent, Gunung Padang etc

The Cyan circle stands for shamanistic nomadic tribes.

The yellow circles are major buddhist sites.

Afghanistan Bamiyan Buddha Statues, keep getting blown up by Taliban

Western Nepal, supposed birthplace of Gautama Buddha

Tibet, Tibet :lol: 

Red Circles are South Indian Peoples

Purple Circles are Middle Eastern/Aryan Peoples

? Nomads West

Highly speculative that the Göbekli Tepe civ. was founded by central asian Turks, but possible.

? Nomads East

? East

I'm not sure how far into India the Cambodians got if at all.

Okay now the interesting stuff. Where did Hinduism & the South Indian people come from?

Recent genetic analysis showed that the north and south indians were distinct tribes. And that the closest relatives of the South Indians live on the Andaman Islands click, home of pretty much the only uncontacted tribe in the world outside of the equatorial jungles(if you don't count getting shot at with arrows as contact:grin:.). So where did their ancestors and therefore the ancestors of the South Indians come from? Especially since they likely had a hand in the formation of the Indus Valley Civilization. Although that culture also might have come from the middle east, or both.

Three options in my opinion.

? South Cambodia

? Indonesia

And the last one is the most far out one.

The big double circle ? to the south

Some (nationalist) Tamil writers keep insisting that their people came from a now sunken continent south of South India. Commonly known as Lemuria (note, location just a guess). Considering Graham Hancock keeps on piling up credible evidence in support of his theories, and you can see most of it anyways on satellite images. The recent genetic evidence that the South Indian didn't come from the north, amonst other things is why I think it's a valid option.

Personally I think Lemura = Madagascar, or at least Madagascar is what's left of it, the plant life is pretty similar if you compare Sri Lanka & South India with Madagascar.

Just a theory, who knows.

About drugs and Hinduism/Buddhism. Not even a question for Hinduism.

I think early Buddhists were stoners & shroomers for sure. Nepal is the Cannabis diversity hotspot in the area considering the size of the country, only rivalled by the Altai Mountains in Central Asia. Also note the orange shroom on the map, that's Chitwan National Park, a particulary low elevation & tropical area within Nepal, famous for shrooms. If Buddha were to smoke some charras at his home town, he could levitate there in like 5 minutes :lol:.

Not so sure about late buddhist, might just copied the style sober, or they might genuinely reach exactly the same states naturally.

Tibetans are different..No known drug culture at all. Still they went faaaar out. Masters of ego death. Check this out, 3D model of an 2D Thangka: click click2