The state of having absolutely no ability or desire to participate in anything beautiful, useful, noble, or artistic. It describes someone who not only lost the confidence or the energy to create, but who decided that these kinds of endeavors were a waste. The human spark is extinguished from such a person and all that is left is a hollow consumer shell.

Antonym of Bemused, the state of being inexplicably distracted, which was thought to be a result of being visited by one of the mythical Muses, who granted talents in the arts and sciences.

While only a Muse can Bemuse someone, many people and groups are capable of Demusing others, including fraternities, Joel Osteen, shift supervisors, Clear Channel Radio Stations, Jeff Foxworthy, people who make Disney movies, anybody who works for Verizon, Tom Clancy, Thomas Kinkade, Paula Deen, Instagram, Reddit, the Grand Theft Auto franchise, etc.
A: He used to be so smart and creative, now all he does is drink on the weekends and play video games. When did he get demused?

B: He went to WVU.

-Urban Dictionary