It's fun to make up titles. This one prompted the observation that, all too often, a duo is a duel whether of like or unlike instruments.
I have just been describing how a pair of young students learned to sight-read truly musically by reading together, first taking turns listening to one another, then as a duo actually sight-reading together.
They know something I never learned, namely that listening is the basis of it all from the very outset through to the deepest adult enjoyment. Actually, that last sentence is not quite right: They know something which I was never taught but had to learn the hard way...