When did people stop referring to their bosses at work as “Mr./Ms.”?

Posted by excessively314@reddit | AskAnAmerican | View on Reddit | 627 comments

I’m almost 30, have been working for 12 years or so, and even in serious positions, I’ve always referred to my boss/superior by their first name per their introduction. In older movies & TV, even adult men refer to their boss as “Mr. Lastname”. I’m curious; when did this fall out of fashion?