Childhood: "I'll make the next World of Warcraft but with better graphics and cooler weapons!"
Reality: Spending 6 months debugging collision detection only to have your game downloaded by your mom and that one supportive friend who gives it a 5-star review despite never making it past the loading screen.
The gap between gaming fantasy and game dev reality is basically the distance between "I'm having fun" and "I'm questioning every life choice while staring at a semicolon for three hours."