>>12010017this graph is dunning kruger effect
Short version: Summed up without memes it means "you don't know what you don't know."
Longer version: As you learn about a new subject, each new thing you learn gives both answers as well as raises new questions. The ratio of discovering new answers to learning new questions is what gives creates Mt Stupid. Eventually if you get more answers and don't get any new questions, you'll reach the mountain top. I suspect the height of Mt Stupid is different for different topics, in that some topics give more questions than answers and visa versa.
Neat little trivia:
the opposite of dunning kruger effect is called imposter syndrome