I think he's saying
"want some gum? want some gum? want some gu-um?"
Seriously, I've always heard it as "what've I done, what've I done, what've I done....", with the last "done" being broken into two syllables.
On "Go Insane," I've always heard, "Say is she.... oh... oh... loving you.... Say is she... oh... oh... loving you....", etc., repeated until the song fades.
Johnny Stew