When kids do linear algebra or they rise to the level of GM in chess within the first two decades of their lives, such people are obviously geniuses. Their intelligence is undeniable.
But it's like moral/spiritual geniuses aren't recognized in the same way, if at all. How come their intuitive expertise isn't recognized so easily ?
Aren't those subjective things? It's easier to measure something like chess skill or whether or not someone can do complex math, but harder to quantify someone's morality.
Mozart was a child prodigy. He started playing piano at age 4, and at age 5 he started composing piano pieces that are still played today. He wrote a symphony at age 8 and an opera at 14. There is a legend that as a child, he heard a choir sing an Allegri piece and went home and transcribed the entire thing from memory.
I think with art it's not so much the result but the process that make a genius. For example there is this guy that just has to look at some landscape for a minute ... and then he can paint it from memory in increadible detail. That's objectivly something that most humans just can't do, that's why it's impressive.