A good lyric...

can evoke meaning in your brain, particular to you. It has to have just enough vagueness to connect to a myriad of memories, and specific enough to tug at the string tied to your emotions. Like this one:

from Hide and Seek
by Imogen Heap

...
Mmmm whacha say,
Mmmm that you only meant well?
well of course you did
Mmmm whacha say,
Mmmm that its all for the best?
Because it is
Mmmm whacha say?
Mmmm that it's just what we need
you decided this
whacha say?
Mmmm what did she say?
...