sophomania

[imifumei.livejournal.com]

sophomania n. Greek (sophos, wise; mania, madness or excitement): overblown opinion of one's own intelligence, delusions of superintelligence.

Usage:

The rampant sophomania from every party seems to make meaningful debate in any political forum impossible.

Or

My first date would have been better if he had left his sophomania at home but instead he spent the entire time explaining things to me like I was a six-year-old.

This one is special to me as it was bandied about a lot when I was in college. Check out the entry on Dictionary.com!