Today I googled "is there a term for mishearing what someone says" and landed on the Wikipedia entry for Mondegreen:

A mondegreen (/ˈmɒndɪˌɡriːn/) is a mishearing or misinterpretation of a phrase in a way that gives it a new meaning. Mondegreens are most often created by a person listening to a poem or a song; the listener, being unable to hear a lyric clearly, substitutes words that sound similar and make some kind of sense. The American writer Sylvia Wright coined the term in 1954, recalling a childhood memory of her mother reading the Scottish ballad "The Bonny Earl of Murray" (from Thomas Percy's 1765 book Reliques of Ancient English Poetry), and mishearing the words "layd him on the green" as "Lady Mondegreen".

"So there is a term for mishearing," I thought. "Cool!"

When I was a young girl, we learned the song "Frère Jacques" in our English elementary school. The correct lyrics were:

Frère Jacques, Frère Jacques,

Dormez-vous? Dormez-vous?

Sonnez les matines! Sonnez les matines!

Din, din, don. Din, din, don.

I did fine with the first few lines, but started making up my own lyrics by the third line. My "Frère Jacques" sounded more like:

Frère Jacques, Frère Jacques,

Dormez-vous? Dormez-vous?

Semma lamma teena. Semma lamma teena.

Ding, dang, dong. Ding, dang, dong.

When I was in high school, Canadian band Rough Trade had a Top-20 hit with "High School Confidential." The song—about the narrator's unrequited lust for a female classmate—includes this verse:

Teenage Brandos stalk her in the halls. (Stella!)

They tease her with cat calls

She's a combination

Anita Ekbert, Mamie Van Dorne

But in the pre-Internet days, I had no way of knowing that my understanding of the last two lines of that verse was wrong, for I heard, "She's a combination of Nita, Ekberg and maybe Van Doren." To this day, whenever I hear the words "combination of," my mind immediately fills in the rest of the line with "Nita, Ekberg and maybe Van Doren."

My mondegreens are not limited to songs. Between 2009 and 2011, I was part of a cohort of executives in the Public Sector Leadership and Governance Program run out of the University of Ottawa. One of the women on that course found it amusing whenever I misheard something. On one of our field trips, while in a large boardroom in Edmonton, the presenter started his presentation and said what sounded to me like "Coffee will be coming around." "Wow," I thought, "they're going to bring coffee right to our tables! How civilized is that?" Normally, we had to get our own coffee from a table at the back of the room or in the hall just outside the room. I turned around to look at my friend, who was laughing. She had probably misheard the presenter as well and could see what I was thinking, only she had figured out faster than I that he had really said, "Copies will be coming around," referring to paper handouts of his presentation slides.

But I wasn't the only one to mishear things. While on a field trip to New York with this same cohort of program participants, a presenter stood up at the front of yet another large room and said what most of us at the back of the room heard as: "Hi, I'm really nervous." One colleague, clearly wanting to put the young man at ease, called out, "Don't be nervous. We're really nice." The presenter looked confused and people at the front of the room started to chuckle, for they had heard what the man had really said: "Hi, I'm Rudy Narvis."

When I told my daughter what I was writing about this evening, I said with enthusiasm, "I learned the word for misinterpreting what you hear." I expected her to say, "Oh, what's that?" Instead, she quickly replied: "Mondegreen, right?" That's my girl. I bet she never said, "Semma lamma teena" when singing "Frère Jacques" in elementary school!