"When I read things like this it makes me sad, because my imagination is nowhere near as active as this."

It's actually a fun exercise, and educational. Make a list of some dirty nasty words you'd like to find in Louie Louie. Or even some innocent ones. Make it 10 or 20, let's say, but try to avoid the real lyrics. (Don't look them up in advance, though, that will scramble the results.) Read it over a few times to familiarize your brain with what's in there. Now listen to the song. I virtually guarantee you will now hear at least some of those words in there. When you are actively listening for something, you tend to hear it.

Since no-one else has used the word so far in this discussion, see also the idea of Mondegreens: https://en.wikipedia.org/wiki/Mondegreen