Forward-pointing as well as recapitulation of past events is important: again Tristram mentions Uncle Toby's courtship of Widow Wadman, promising still again that he will tell that story later. And he will tell it, in every detail, in the last two volumes of the book.
The shattering of Walter's hopes is very funny — because he is caught in his own teasing — and also very poignant. Tristram feels compassion for his father, but he is always able to laugh, at himself and at his own difficulties as well as at others. He'll laugh at Walter's hand resting on the chamber pot (shortly), and that is one of the justifications for his describing Walter's position with the eye of a painter and a poet
Having gotten his father to the point of grieving over Tristram's nose, the author must now take an extended tour backward to explain.
