The title is a play on the Boys Town motto, "He Ain't Heavy, He's My Brother." A pop song version by The Hollies was a top 10 hit in 1970, the year before this episode aired.
In this episode, Mary and Rhoda are planning a trip to Mexico. Mary says that she knows how to speak French; however, she denies knowing any Spanish. In the season one episode Divorce Isn't Everything (1970), Mary claims the opposite is true. While the ladies are discussing a possible trip to Paris, Mary says she is fluent in Spanish, as opposed to knowing any French.
First of three episodes directed by Jerry Paris, who as an actor played Jerry Helper, Rob and Laura Petrie's next-door neighbor on Moore's earlier series The Dick Van Dyke Show (1961).
The places in Mexico Mary considers vacationing at , Puerto Lorenzo and San Leon, are fictional and do not exist