Probably the earliest for me was in the Alphabet Song, which I learned before I actually learned to write the letters. I thought elemeno was one letter. It sounded really cool, and boy was I disappointed to learn that there was no such thing!

From about the same period of time: a one-horse soap in sleigh.

In and around the lake, [mollusks] come out of the sky and they stand there.

[media=https://www.youtube.com/watch?v=DwPWGUhEtP0]

“There’s a bathroom on the right”

For the longest time, I thought in the song Killer Queen by Queen that Gunpowder Gelatine was "cut by the guillotine" which I thought was a double entendre for Mary Antoinette was well as sexual reassignment surgery.

The Pretenders Middle Of The Road:
Middle of the road is trying to find me
I’m standing in the middle of life with my pants behind me
[media=https://www.youtube.com/watch?v=-KosB3XJO_s]
I shared this misheard lyric with a friend who now cannot unhear it this way. 😆

I thought it said "Put me in cold" instead of "Put me in Coach."

Centerfield

[media=https://www.youtube.com/watch?v=YqY7e4bP9PQ]

When I was kid, I thought the song Kyrie by Mr. Mister went, "Carry a laser through the road that I must travel", until my parents told me that it's "Kyrie Eleison through the road that I must travel".
'

My friend thought the lyrics in the U2 song "Where the Streets Have No Name" by U2 were, "I wanna feel sunlight on my face. I see the toaster disappear without a trace." We teased him about it so much! 😄

For me, it was, "There's a bathroom on the right."

For quite some time, I thought the line in Bad Moon Rising by CCR was "there's a bathroom on the right."

My daughter's best friend thought the chorus in Garth Brooks' "I'm Shameless" was "I'm shaving."

My sister used to sing a song called centerfolds, the actual lyrics are, "my memory has just been sold" she would sing my lovery has just been sold

Peter Kay does a few on one of his stand up show

The hot dogs go on titanic

In ''The Real Slim Shady'' I used to hear:
''My mum is on your lips, my mum is on your hips'' instead of ''bum'' and “lips”

I’m not joking when I say I found out I had been singing it wrong my whole life just a couple of weeks ago

There was the Neil Diamond song where he stated that "... He'd much rather be the Reverend Blue Jeans."

Flash Dance “Take your pants off/and make it happen
You just come on like you can dance right thru your life”
(yes, there is a recurring theme here, I know 😆)

It is not “ mama yo quiero “ , it is “ mamae eu quero. She was a Portuguese speaker, as far as I know, not Spanish.

Not trolling, as a child I heard on jingle bells, "Dashing through the snow on a one whore soap and sleigh, all the hills we go laughing all the way" I hate the taste of soap, especially around Christmas time. ☹

I never actually did. I'm just here because I love mondegreens.

Also, when Jimi Hendrix found out how people were singing that one line in Purple Haze, he would sometimes sing it in the wrong way that they were doing it, just to be silly.

"Scuse me while I kiss this guy!"😆