The speaker distinguishes between two kinds of cheerful-looking people. He says he respects the noble man who can keep a bright face and calm manner even when he is full of trouble, acting as though everything were serene. But he makes clear he likes another type better: the person who needs no brave front because he is naturally buoyant, “lively as a kangaroo,” beaming and shouting with pure delight when life is actually going well.
It is a playful, gently comic poem. The word “noble” gives the first figure real dignity, but the second wins out through sheer joy and energy. The exaggerated kangaroo image keeps the tone light rather than moralistic. The mood feels like a wry, good-natured preference for honest gladness over admirable but effortful composure.