I have never seen a Nun smile or look pleasant.

The Catholic Answers

You know Nuns only from a distance, if you know them at all. Nuns do not mistake excitement for happiness, but there are plenty of smiles in their own convent environment. In the streets you may not have seen a Nun laugh. But the sight of poor humanity in the streets, rushing and struggling, and worried even in the midst of its giggling, is not calculated to make a thoughtful person laugh. Yet as for looking pleasant, I’ll guarantee that the tranquil face of a Nun is a much more pleasant thing than the face of the average woman of the world.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty