Many a man in love with a dimple makes the mistake of marrying the whole girl.

The joke turns on a deliberate mismatch of scale: a “dimple” stands for a small, alluring feature (or any single attractive trait) that becomes the focus of infatuation. “Marrying the whole girl” punctures the fantasy by reminding the reader that marriage entails commitment to an entire person—habits, flaws, history, and change over time—not merely the charming fragment that sparked desire. Leacock’s humor critiques romantic idealization and the tendency to confuse attraction with understanding. Beneath the wit is a cautionary point: love can be selective in what it sees, and lasting partnership requires a fuller, more realistic apprehension of the beloved.