Source: The Story Behind Alice Cooper’s First Hit, ‘Eighteen’ – WSJ
“The last line of my lyric to “Eighteen” was supposed to be “I’m 18 and I hate it.” But as I neared the end of my vocal in the studio, I decided to flip it to “I’m 18 and I like it.” I wanted to turn the teenage angst around.
That was a surprise to everyone in the control booth. With my earlier lyric, the song was a good hard rocker. But by flipping the line, the song became a statement.”