disillusionment

noun

Etymology: From dis- + illusion + -ment.

1. A feeling of disappointment, akin to depression, arising from the realization that something is not what it was expected or believed to be, possibly accompanied by philosophical angst from having one's beliefs challenged.

   “But till I am thirty, I know that my youth will triumph over everything- every disillusionment, every disgust with life.”

   “I catch on your face the old sad smile / Of our ancient disillusionment, / When the ardent crowd tries to beguile / Your world-old soul to impassionment.”

2. The act of freeing from an illusion; the state of being freed therefrom.

   “It is a very wholesome and regenerating change which a man undergoes when he "comes to himself." […] It is a process of disillusionment. The scales have fallen away.”