Winters in north India is no joke. It may not snow and rarely do people freeze to death, but single digit mercury temperature is not uncommon. If it rains in winters, then the situation becomes even worse. Yet surprisingly very few Indians invest in centralized heating and we could seamlessly move from inside of home/office to outside.
On the contrary, wearing a jacket indoors in Europe is kind of an insult to the host. It is a subtle accusation to the host that the hospitality is not warm enough. In India, removing the pullovers or layers of clothing might hint that you are getting a little bit too cozy. How the same action/inaction have totally different cultures . I wish I had a cool T-shirt that explains people “I am from an alien culture and not to think too much in trying to interpret my habits”