"When in Rome" is a popular saying that means when you are in a different place or culture, you should adapt to the customs and behaviors of that location. The phrase suggests that it is respectful and wise to follow local traditions, especially when traveling or living in a new environment. The expression originates from the ancient practice of adapting to the ways of the Romans when visiting Rome. It highlights the importance of cultural sensitivity and understanding, encouraging people to embrace new experiences while respecting the norms of the community they are in.