The practice of referring to someone much older than oneself by their first name can vary among English-speaking cultures. In the United States, it is relatively common and considered more acceptable in casual and informal settings, especially when there is a close or friendly relationship between the individuals.
However, in other English-speaking countries, such as the United Kingdom, Canada, Australia, and many others, the use of titles or more formal forms of address for elders and people in authority is often emphasized. In these cultures, it might be considered impolite or disrespectful to address someone significantly older or of higher status by their first name, especially upon first meeting or in more formal situations.
The use of formal titles like "Mr.," "Mrs.," "Ms.," "Sir," or "Ma'am" is more prevalent in these cultures as a sign of respect. In professional or formal settings, even last names preceded by titles are commonly used as a polite form of address.
It's essential to be mindful of cultural norms and preferences when addressing someone older or of higher status. When in doubt, err on the side of formality, and if the person indicates they prefer a more casual approach, you can adjust accordingly. Showing respect and consideration for cultural differences is a crucial aspect of effective communication in a diverse world.