So many of Hawthorne's tales are richly allegorical and have a definite didactic purpose. This tale is certainly no exception. The key to establishing the theme is therefore to identify what message or lesson is communicated through the action. Clearly, the focus is placed on age early on in the story through the reference to the somewhat shady and mysterious background of Dr. Heidegger and his lost love, whose death he is implicated in. Note how the rose is introduced as a symbol of his relationship and his love for his former lover:
"This rose," said Dr. Heidegger, with a sigh, "this same withered and crumbling flower, blossomed five and fifty years ago. It was given me by Sylvia Ward, whose portrait hangs yonder; and I meant to wear it in my bosom at our wedding. Five and fifty years it has been treasured between the leaves of this old volume."
Just as the rose has withered, so has Dr. Heidegger and his guests have withered. Yet, even though Dr. Heidegger manages to restore the beauty and vigour of the rose, in the same way that his guests have their youth restored, the transitory experience shows him the benefits of old age and the wisdom that comes with it instead of the follies that inevitably characterise youth. Note what Dr. Heidegger comments about the Water of Youth and its loss after seeing his guests repeat their youthful indiscretions:
Well--I bemoan it not; for if the fountain gushed at my very doorstep, I would not stoop to bathe my lips in it--no, though its delirium were for years instead of moments. Such is the lesson ye have taught me!
The subject of this story is therefore age and our perhaps natural desire to wish to go back through time to our youth and our naive belief that we would not repeat the same mistakes. This story questions such beliefs and also demonstrates the richness of old age, challenging our views about aging and growing old.