IMHO this is the most touching episode of the series. You really feel for Jan. She is the middle child and being confused with her older sister and younger sister. She gets a wig to make herself stand out. Yet all of her siblings and friends make fun of her. In the end her fellow middle brother child is the only one in the family that did not make fun of Jan. He introduces her at the party and when the kids think its a joke, the look on Peter's face is horror. Peter was the only one in the family that did not make fun of Jan with the wig.
Chris Knight was commenting that he never realized until recently watching that it was an episode of the middle kids sticking together. Jan had the most beautiful hair so everyone could not understand why she would want to hide it with a hideous black wig. Walk in Jan's shoes and you will know.

One of the best episodes and the most touching in my book.

Definitely a great episode.

I've watched the show since its original run, but until Chris Knight mentioned this in the Brady Bros latest podcast, I didn't really notice that Peter himself did not make fun of Jan's wig. Greg and Bobby did, Marcia and Cindy did, but Peter never criticized it and you could see how bad he felt when Jan thought her friends were making fun of her. A case of the middle kids sticking up and looking out for each other.