**Private Quelch and the Nickname "The Professor"**

Private Quelch, a character in the novel "The Secret Life of Walter Mitty" by James Thurber, is given the nickname "The Professor" due to his intellectual and academic demeanor. Quelch stands out among his fellow soldiers due to his seemingly endless knowledge, which he often showcases with his detailed lectures and explanations.

**1. Intellectual Knowledge and Academic Prowess**

Private Quelch possesses a vast amount of intellectual knowledge, which he acquired through extensive reading and studying. He is well-versed in a variety of subjects, ranging from history and geography to mathematics and science. Quelch's academic prowess is evident as he consistently demonstrates his ability to answer complex questions and solve intricate problems.

**2. Pedantic Behavior and Lecturing Tendencies**

Quelch's pedantic behavior is a defining characteristic that contributes to his nickname, "The Professor." He often lectures his fellow soldiers, imparting his knowledge and correcting their mistakes. Quelch's desire to share information and correct inaccuracies stems from his belief in the importance of education and the pursuit of knowledge.

**3. Attention to Detail and Perfectionism**

Another reason for Quelch being called "The Professor" is his attention to detail and perfectionism. He meticulously follows rules, regulations, and procedures, ensuring that everything is done correctly. Quelch's perfectionism often leads him to correct his comrades' mistakes, reinforcing his role as an authority figure within the group.

**4. Lack of Social Skills and Isolation**

Despite his extensive knowledge, Quelch lacks social skills and struggles to connect with his fellow soldiers. His excessive lecturing and correcting often alienate him from the group, making him an outsider. Quelch's isolation further reinforces his nickname, as he appears more like an academic figure separate from the rest of the soldiers.

**5. Comic Relief and Satirical Representation**

In "The Secret Life of Walter Mitty," Private Quelch's character serves as a source of comic relief and a satirical representation of the overly intellectual and pedantic individuals. His exaggerated behavior and obsession with knowledge highlight the absurdity of excessive intellectualism and the potential disconnection from practical realities.

In conclusion, Private Quelch is referred to as "The Professor" due to his intellectual knowledge, pedantic behavior, attention to detail, and isolation from his comrades. The nickname adds depth to the characterization and contributes to the satirical tone of the novel.