system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the word 'potato' associated with mental retardation?
gpt
It's from a movie called "The Ringers" where some people pretend to be mentally challenged in order to compete in the special Olympics. In order to convince people he is mentally challenged, one of these "ringers" says: "I can count to potato!"

There is also the meme of saying that a picture of video of low quality was taken/recorded by a potato and you'll often see references to "potato quality."

Both of these have led to an association of "potato" with low quality or poor intelligence.