Most experts agree the predominant interpretation of "When I Was One-and-Twenty" by A.E. Housman is that of a young man failing to heed the advice of an older man on the subject of love, and as a result, he experiences the pain of a love lost. The poem combines the themes of the energetic foolishness of youth with that of loss and pain.
The poem opens with an older man advising the 21-year-old man to give away money and wealth, but never his heart. The 21-year-old admits how useless it was to try and warn him of the dangers of love because no one will listen at that age. Then the older man continues to warn him that the cost will be a painful experience. When the 21-year-old turns 22, he replies to this man's wisdom saying, "And oh, 'tis true, 'tis true!" (line 16). He admits, after he has gone out and ignored the advice and paid the price, that the cost is a painful one to pay. Housman's style is lighthearted and musical, but the message of his poem is poignant and full of wisdom. This poem reiterates that love is not always logical or wise and the young man in this poem had to learn that through experience.