Coined and popularized by renowned Cracked Editor David Wong, this term is a derivative of the term sticker shock. It refers to the feeling of shock and dismay one encounters when discovering how difficult it really is to accomplish a goal. The term is usually used to refer to long term goals, such as getting a degree, acquiring a job in a desired profession, learning a new skill (guitar, a foreign language, etc.), or completing a long term project (remodeling, losing weight, etc.).
While many people of varying levels of intelligence and backgrounds can encounter Effort Shock, it is believed to mainly afflict people in first world, Westernized societies. This is likely due to a variety of factors: parental upbringing, popular cultural influences, the overwhelming choice of professions in Westernized society, and lack of education about one’s desired goal.
While they often initially feel extremely excited, motivated, and prepared, realizing the daunting magnitude, difficulty, and level of effort to achieve the goal leaves the victims of Effort Shock feeling disheartened and lacking motivation. This can lead to the person quitting their goal entirely.
After being told how smart and "destined for great things" he was for the duration of his childhood and teen years, Jimmy encountered Effort Shock when he graduated and realized that smarts alone couldn't get him even a mediocre job.
I experienced Effort Shock when I tried to learn a foreign language after high school, because I underestimated and lacked the motivation and commitment needed to gain any conversational proficiency.