Anyone wanting to learn about how wood grain direction affects woodworking should do a little carving. This is the best way to get some direct experience because wood carving is all about wood grain direction and you can only get clean cuts if you understand the direction and tilt that your chisels have to follow in order for that to happen. In spite of knowing this, I am not anywhere in the neighborhood of being a competent wood carver. I guess that makes me a theorist.
Mike, an American living in Norway