I used to think I was not "talented" at drawing until a girl I was dating gave me that book to read.
I was skeptical at first but after going through a couple of the drawing exercises I was convinced. They are so cleverly constructed to make you step outside of your normal brain and just draw, it's kind of amazing the results.
I'm never going to be an artist professionally but I do actually draw as a pastime now and I have improved substantially.
I think if I had practiced more as a kid and teen I may have pursued art professionally.
Part of the problem is that adults see a kid upset that their drawing isn't very good and say things like "That's ok, you're just not an artist. Not everyone can draw" and people internalize that. It's supposed to make the kid feel better and it might cheer them up in the moment, but it also convinces them that they cannot learn to be better at things they are not immediately good at.
Toxic Feel-Good shit.