But he didn’t learn them note by note, chord by chord from the sheet music or chord chart. Maybe the first few, but after that he began to see patterns that repeated throughout these jazz standards. 4 bars here, 2 bars there, even 8 bars sometimes.
And so once he saw these patterns and got used to playing them, learning the songs as a whole became easier. It’s the same process that enable master chess players to scan a board and sum it up for themselves in an incredibly short amount of time. Chunking.
But it’s not just in jazz that this is relevant. It’s across music. Get used to your chord shapes, get used to playing them across a variety of keys, and you’ll find that they apply in not just the particular song you’re learning at the time, but across a variety of songs.
And while you might not get to 500 by age 22, you’ll notice that the amount of time in which it takes to you learn a new song diminishes bit by bit.