The Story of What Really Happened to Arnold's Parents Is Revealed in the 'Hey Arnold' Movie

What happened to Arnold's parents in Hey Arnold! was a mystery that hovered over Arnold throughout the show. Arnold longed for a traditional nuclear family, but eventually learned to accept his unconventional home life with his grandparents.

In Hey Arnold! The Movie, which came out in 2002, we finally learned the true story of what happened to Arnold's mom and dad in the fictional jungles of San Lorenzo.

In the Hey Arnold! episode "Parents Day," Arnold is upset that his parents aren't around to compete at the "Parents Day" tournament. He ends up bringing Grandpa, but it stirs up Arnold's feelings about missing his mom and dad.

Arnold asks Grandpa to tell him the story of what really happened to his parents. Grandpa says that Arnold's dad was a scientist, who went to the fictional San Lorenzo to help find a cure for an illness affecting the region. That's where he met Arnold's mom.

The pair fell in love eventually and traveled the world together. Grandpa said that they were meant for each other.

After having Arnold, his parents were called upon again to help "mountain people" with another bad illness, but Arnold's dad refused because he had Arnold to take care of.

He eventually changed his mind when he learned that the affected population would be completely wiped out if they didn't get help.

Arthur's parents flew off on a small plane and were never found again.

In Hey Arnold! The Movie, Arnold and his friends travel to San Lorenzo, where they discover that Arnold's parents contracted a "sleeping sickness" that causes all adults to fall into a deep sleep.

Arnold's parents had been asleep for years. The crew eventually found a cure for the sickness, and Arnold and his parents finally united before Arnold began sixth grade.

While some fans praised the way that the Hey Arnold! movie was able to tie up plot lines and give closure to Arnold's most pressing question, others were dissatisfied and thought the ending was unrealistic.

One fan wrote in the Hey Arnold! subreddit that they thought it would have fit Arnold's story better if his parents had passed. They argued that the movie's conclusion was unrealistic and took away from Arnold's struggle to accept his different family life.

While Hey Arnold! is a cartoon where everything doesn't have to be realistic, it is odd that the show calls the "sleeping sickness" deadly but also allows his parents to live with it for 10 years without medical help.

A dark perspective from Redditor @Awkward_Swordfish581 is that while Arnold's parents were alive, they weren't completely functional mentally after going through such a long coma and sickness. In this case, Arnold would be getting the picture-perfect family he longed for while still not receiving the parental support he needed. He'd have to step up and take care of his own parents, instead of the other way around.