Final answer:
Dexter is disappointed when he first sees Judy because she falls short of his idealized image of her; her beauty and charm are ephemeral and do not promise emotional depth. Despite his eventual engagement to another woman, Dexter remains fixated on Judy, illustrating his struggle between attraction and the recognition of her superficiality. Ultimately, he realizes the loss of both Judy's beauty and his own youthful illusions.
Step-by-step explanation:
Dexter's disappointment upon seeing Judy for the first time stems from the disparity between his glorified image of her and reality. Dexter, engulfed in his idealized perceptions, is confronted with Judy's more mundane and human characteristics, such as her capriciousness and superficiality.
His disillusionment is a product of recognizing that Judy's beauty and charm do not equate to depth or constancy; her allure is transient, and she manipulates her suitors' affections without malice or intent, leaving a trail of ensnared and heartbroken admirers, including Dexter himself.
As his experiences with Judy unfold, Dexter grapples with the duality of his attraction to her and his acknowledgment of her flaws. Despite his engagement to Irene Scheerer, Dexter remains ensnared by the enchantment of Judy's presence and the youthful aspirations she embodies.
However, over time this enchantment fades, and upon hearing Devlin's casual mention of Judy's loss of beauty, Dexter experiences a profound sense of loss—realizing that time has eroded not only Judy’s allure but also his own youthful dreams and desires.