The sense of homecoming abroad is not necessarily a function of cultural proximity. I experienced it in Mexico as well. I found that an entire thesis, titled Hindu America, has been written on similarities with Aztec and other ancient civilisations of the region. The author, Pandit Chaman Lal, theorised on an early sea link between India and America, long before Columbus landed there. The thesis has not found much support, but the empathy an Indian feels on reaching Mexico is unmistakable.
For Cambodia, or Kambuja desa as known earlier, historic links are well established. Evidence exists of adventurous seafarers from Orissa and south India landing there and in other parts of Southeast Asia in the early years of the Christian era, carrying traders, scholars, artists, religious teachers; but not conquerors or colonisers. The mission was cultural, not imperial. Local rulers adopted Indian names, customs, alphabets and Sanskrit. Their most famous dynasty was founded by Jayaraman II and extended to Jayaraman VII. Brahmin priests still serve the court of King Sihanouk, though Buddhism has become the state religion.
