a glitch in a game that results in gaining money basically for free.

taken from ragnarok online.

alternately; anything that corresponds in real life, like confusing clerks at the grocery store to enter discounts on items that are far too high.

A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.