All the time, lol. I have to really listen intently to get all the lyrics
(or relisten to a song over and over until I memorize it), otherwise I don't understand what the singer is saying or I mishear something. I initially had trouble getting into certain artists like Korn and Rob Zombie, because the singing sounded like pure gibberish to me.
I relistened to "The Frayed Ends of Sanity" by Metallica the other day, and I had only just registered some of the lines, particularly
"Now the candle burns at both ends". I was like... "Uh, that was in the song?!"