China and India - these two nations have been in geographical proximity to each other, both have had civilizations dating back thousands of years, both have had a rich political, cultural, military and philosophical history. But the two civilizations developed completely independent of each other with only minimal contact between them. The reason for this is due to the Himalaya mountain range - the highest in the world - separating the two great nations.
The Himalayas are the reason why China’s culture, political reach and military prowess never even touched India for millennia - thereby letting India avert the same fate as Southeast and East Asia where Chinese ethnic, linguistic and cultural influence has been heavy. But conversely, the Himalayas also isolated China from Indian cultural, political and military reach - and prevented ethnic mixing. Therefore, for a long time, both nations and their peoples saw the other as this mysterious alien land with unfamiliar languages, unfamiliar culture, unfamiliar everything.
