Sorry but this is false. Sensing pain can mean it's already too late and damage is already occurring.
Would you learn to fly a plane from a book? "When you are upside down in a flat spin, you may be in trouble"..
Get a good teacher who can guide you through the foundation alignments and do hands-on adjustments when you are starting out. A book can certainly help but it can't be your only guide.
Pain isn't necessarily a bad thing and doesn't necessarily mean 'damage is already occurring'.
If you are remotely in touch with your own body and athletic you can teach yourself yoga from books/youtube/podcasts. The best progress I had doing yoga was when I was living in Taiwan and 90% of the class was in Mandarin (which I don't speak). It caused me to focus more and listen to my body.
Would you learn to fly a plane from a book? "When you are upside down in a flat spin, you may be in trouble"..
Get a good teacher who can guide you through the foundation alignments and do hands-on adjustments when you are starting out. A book can certainly help but it can't be your only guide.