It is hardly useful if you trustingly play through variation after variation from a book. It is a great deal more useful and more interesting if you take part actively in the analysis, find something yourself, and try to refute some of the author's conclusions.

Training in analysis (like any other form of chess training) should be treated very seriously.

Black is now in desperate need of a good idea. Or, to put it standard chess notation, +-

As a rule, pawn endings have a forced character, and they can be worked out conclusively.

It is not possible to become a great player without having learned how to analyse deeply and accurately.

Often you will find the opposite situation. The author seems to have interesting ideas, but he is not able to illustrate them with decent examples. If a grandmaster is commenting on one of his own games, then there is usually not any problem: his general thoughts are closely tied up with what is happening on the board. But as soon as he starts writing an article or book on a different theme the difficulties begin, as he may not have suitable material to hand.

It is hardly useful if you trustingly play through variation after variation from a book. It is a great deal more useful and more interesting if you take part actively in the analysis, find something yourself, and try to refute some of the author's conclusions.