Surprise sideways leap by an individual to the shoulder of an unsuspecting person (the crunch) for the purpose of creating new awareness in the recipient. An LC is not intended to inflict physical harm but rather is intended to be symbolic of the need for a change in one’s direction in life. The result is discombobulating of mindfulness of the recipient in order to gain new awareness. The bemusement of the recipient may last minutes, hours, days, months, years, decades or even for life.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.