The Red Pill
According to Wikipedia:
The red pill and its opposite, the blue pill, are pop culture symbols representing the choice between the blissful ignorance of illusion (blue) and embracing the sometimes painful truth of reality (red).
The terms, popularized in science fiction culture, derive from the 1999 film The Matrix. In the movie, the main character Neo is offered the choice between a red pill and a blue pill. The blue pill would allow him to remain in the Matrix, a fictional computer-generated world. The red pill would lead to his escape out of the Matrix and into the “real world”.
This is the famous scene from the Matrix where the hero takes the red pill: