macademia nut

A college student/graduate wif a hard tough "shell" dat is difficult to "crack" --- i.e., he is so "rigidly wrapped up" in his dusty boring books dat he cannot effectively interface wif da common man.

Faust was famously suffering from being a major macademia nut --- he'd learned a lot about a variety of literary subjects, but he didn't know da simple nuances of life, such as how to have fun or da ways of effectively communicating with people.