Arnie, the best witness hitherto seems to be that anonymous GUEST on 09 Oct 10 - 11:06 AM. However, that version might be a parody of an affirmative original.

You'll have a ball when you're spreken der Deutsch - not while learning, to be sure. If the last three words of this line are original, they are deliberately wrong German, somewhat self-contradictory. (A well-known variant is "I wish I could sprechen Sie deutsch".)

I googled quite a bit and found no further evidence of the song; the question is still open.

Actually, learning any foreign language is very difficult. To aid your memory, learn songs (or arias) by heart, and read books you really like.