Travelling in India can be tiring as one has to adapt to the crowds, noises, spicy food, warmth, bugs, stares, animals, smells, traffic, diseases, pollution, gigantism, diversity, lack of privacy, poverty, beggars, touts, etc.
At one point or another, you will be pushed out of your comfort zone. For me, being continuously observed (well, stared at!) was definitely the biggest hassle.
To fully enjoy the country, take your own needs into account. This would differ from person to person and might include: avoiding large cities if crowds make you uncomfortable, taking vitamins if your new diet makes you feel weak, deciding in advance on your "beggar policy" if you struggle with insisting beggars, etc.
And be open-minded!
What would prevent you to go to India?