Ryan Gosling learning piano for La La Land -- Thoughts?

[Bob]

From what I saw on this and other videos, he learned music by rote.  I wonder how much music background or even piano he had before this though.  These videos say he didn't learn to read music at all.  And the piano teacher mentions he spent two hours a day for five days, sometimes even six days a week!     If it's actually him playing on the recording, I wonder how much it's edited. 

Any thoughts?  Esp. about learning something like this by rote.  On one hand, it's keeping him musically illiterate.  On the other you have a finished-enough performance.  I saw someone without a music background once teaching kids a musical (probably still does this) and she did it by rote, just playing the music over and over and eventually the kids learned it without much understanding of music but they could perform it well enough to do a musical.  How Gosling did this reminded me of a more extreme version of that.

It also makes me wonder if I'm really doing the same thing but reading and interpreting the music myself, but essentially just repeating it a lot and still learning it by rote.